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OnStart 310, Stopwatch

Sale price: $15.00 Regular price: $24.99

Essential training functions: stopwatch, countdown, and 50 split times.

Color: Select a color
Size: Select a size
Sale price: $15.00 Regular price: $24.99

Free shipping over $49

Final Sale: No returns or exchanges

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Free pickup

San Francisco, 735 Market St. Options

Select an available color and size to see options.

Model: 8374969

Product Features

OnStart 310, Stopwatch | Our dedicated team of runners has designed this watch for you so you can time your performance and program your interval training

Essential training functions: stopwatch, countdown, and 50 split times.

A photo of the OnStart 310, Stopwatch in use

Measurement settings

Stopwatch (1/100 sec) with 50 split and lap times.


3 countdown modes depending on your sport: Match, Coach, and Up & Down


Pace tracker (Pacer)


Time, date, and alarm.

Battery life

Automatic or manual stand-by mode for optimizing battery life


Rainproof (1 ATM)

Easy to read

Large digits for perfect legibility when you play sports.

Easy to maintain

Manual opening makes it easy to replace the battery.

Questions & Answers

Product Customer Reviews

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531 Reviews
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OnStart 310, Stopwatch,black
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Mid to low range

I was expecting a bit more reliability for the price. As a time keeper at swimming galas, a reliable stop watch is essential when timing 100+ races, but this let met down too many times.

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Nice Chrono

I don't know much about chronos nor what's out there but this one is very responsive and very easy to use.

Good product

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Watch Already Very Good


Nhpc, are you satisfied with your latest purchases

Yes, It is a high accuracy & precision product, which is complied our ISO testing parameter as we are using the above product to carry out material testing at Quality Control Testing Laboratory, NHPC, Liaison Office, Siliguri.

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Not good

This product is not comfortable and handy

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Product was better then I expected. At this price point just go for it.

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Pathetic quality

I have returned the same and taken my money back. Ideally I Shud be asking decathlon to indemnify me as this product was bought and replaced twice yet finally I had to take my money back. It was not in working çondition. Time waste, hapazard parking omg it was a pain

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perfect stop watch

good choise

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Dear Kokozan, thank you for your time in leaving us with a 5-Star rating on our product. We are glad that we managed to delight you with the standards of our product. We really appreciate your loyalty with Decathlon. Please let us know if there is anything else we can improve on in the future. Thank you once again for your time and we hope to serve you again soon! :)


Kalenji Onstart 310 Stopwatcb

Friendly interface and easy to use

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Hi He,

Thank you for taking the time to review our products. We are pleased to hear that this item meets your expectations!

We look forward to more of your reviews and sharing! Plus, the new Decathlon app has been launched and you can now purchase all your favourite sports goods with just a few clicks on your smartphone! Yes, it's now available both in the App store and Google Play Store! Download now and happy shopping!

Thank you for your support and stay safe! :)

Sport on safely!


CSM Digital Leader


ใช้ดีแต่เสียงดังมากค่ะ มีวิธีปิดมั้ยคะ



KALENJI นาฬิกาจับเวลารุ่น ONstart 310 ไม่สามารถปิดเสียงได้ครับ

เพื่อให้ทุกคนได้รับประโยชน์และความสุขจากการเล่นกีฬา อย่างยั่งยืน

Sarawoot Promsriroj (JACK)

Trekking bikes &​ Workshop and​ Triathlon Enthusiasm

Decathlon Rangsit

Tell 020631990

Line ID: Jackphichit



ขอขอบคุณประสบการณ์ในการใช้นาฬิกาจับเวลารุ่น ONstart 310 


Sarawoot Promsriroj (JACK)

Road Running &Triathlon Leader Decathlon Rangsit

Tell +66848336355

Line ID: Jackphichit

Faceboo​k: Sarawoot​ Promsriroj


อยากให้สามารถ lap time ได้ถึง 100

ขอขอบคุณประสบการณ์ในการใช้นาฬิกาจับเวลารุ่น ONstart 310


Sarawoot Promsriroj (JACK)

Road Running &Triathlon Leader Decathlon Rangsit

Tell +66848336355

Line ID: Jackphichit

Faceboo​k: Sarawoot​ Promsriroj



icon-circle-checkmark verified purchase


Благодарим Ви за отделеното време и оценката, която сте дали за нашия продукт. Качественото обслужване, доволните клиенти и предоставянето на възможността всички да спортуват е наша главна цел.

Спортни поздрави,

Екипът на Декатлон България!

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Additional Product Information



  • 80% Acrylonitrile butadiene styrene
  • 20% Acrylic

Inner tent

  • 80% Pcba
  • 20% Battery - Lilo

Stopwatch with up to 50 saved lap times

Up to 99 hrs 59 mins 59 sec and 50 split times (split and lap). The stopwatch measures the following: 1/ split times = Split: the time elapsed since the start, 2/ lap times = Lap: the time elapsed since the last lap time measurement.


When using the stopwatch, the first 50 split times and lap times are memorized. They can be recalled, whether the stopwatch is running or not. You can view the following in the memory: the fastest lap time, slowest lap time, average lap time out of the X saved times, last lap time, penultimate lap time, etc.

Coach countdown

Create your training session to manage your efforts: - your warm-up time (Warm Up) - your acceleration / fast exercises time (Run) - your recovery / slow exercises time (Rest) - the number of run and rest in a series (Repeat) - the number of run + rest exercise series (Series) - your time between 2 series of exercises run+rest (Break) - your end-of-session / stretching time (Cool). Up to 99 series and 99 repetitions.

Match countdown

Countdown with several programmable times (up to 9 blocks and 99 repetitions). Perfect for refereeing a match with several periods of play.

Up and down countdown

Countdown associated with a stopwatch. At the end of the countdown, the stopwatch starts automatically. Perfect when starting a race with a countdown (e.g. at a sailing regatta).

Pacer function: stride pace

The Pacer means you can set a pace per minute with beeps at set intervals. It is combined with a stopwatch. Set the required rate (between 1 and 240 beeps minute), and the stopwatch will beep at this rate to give you the pace.

Perfect visibility

Big screen with a 3-row display.


This product is waterproof at 1 ATM, i.e. resistant to rain and use in a damp atmosphere such as a pool.

Specially designed for comfort and precision

The ergonomics of this stopwatch have been carefully designed so that the buttons are accessible and can be used with precision. The design of the stopwatch and its lightweight construction mean you can hold it comfortably in your hand. Because it is crucial to know precisely whether you have activated the stopwatch, you will hear a click when you press a button. The wide strap will let you keep it comfortably around your neck.

Save your battery

Your stopwatch will not stay on forever at the bottom of your bag. It automatically goes to stand-by mode after 24 hours. You can also switch to stand-by mode manually.

How to choose the right stopwatch

The range: - OnStart 110: stopwatch with 1 split time, time, date, alarm - OnStart 310: stopwatch with 50 split times, Match mode, Coach mode, Up & Down mode, speed pacer; rain-resistant - OnStart 710: stopwatch with 300 split times, Match mode, Coach mode, Up & Down mode, speed pacer, pace tracker, speed tracker, rain-resistant, light - OnStart:



Product testing

Decathlon teams have been designing watches specifically for sports use for 20 years. During development, each model undergoes more than 30 different tests in the laboratory, as well as some tests in the field conducted by our teams of testers.


Essential parts (battery) available: 2 years

Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

Decathlon makes the difference
  1. product-research

    Research and development

    delivers high-quality cost-effective products

  2. State-of-the-art production processes

    minimize manufacturing costs

  3. Optimized supply chain

    reduces retail prices

  4. laptop-checkout

    Minimal retail footprint

    lowers overhead and indirect costs


Size Guide Visual

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