Delvfire Spark Slim Fitness Tracker with Heart Rate Monitor, Waterproof Fitness Watch Activity Tracker with Pedometer, Sleep Monitor, Step Counter, Calorie Counter for Kids, Women, Men - Apple Android

The tracker is small and looks very smart. I love the fact that it's waterproof and you don't need a cable to charge it - you just plug the tracker itself into the USB port. But that's where the positives end. It is inaccurate - brief spells of stepping (less than 50) don't even register. Long runs (distance confirmed by a GPS tracker and Google Maps) register only partly (6km instead of 11km). Heart rate badly underestimated, even at peak of exercise it never shows more than 'slightly elevated'. Consequently calories burned are also significantly underestimated (e.g. an hour-long run at 10kph burned 300kcal, same number of calories burned whether I hike for an hour with a 10kg backpack or without). Finally, calories measured only when active, not while resting. Overall, it's not terrible but you get what you pay for, a pretty poor/basic product.

I had difficulty doing the bracelet up and undoing it which is a great safety feature but very difficult for me. I also have a very small wrist and the face was too wide and bulky. I would have put up with this possibly if I could have undone the bracelet. I needed to use the tightest fixing which could have been my problem.

Been wearing this a few days before I left review!...battery still going after first initial charge!, I went for black and it looks smart. Its seems pretty accurate...as have tested the activity along side my samsung health app on phone and they match!..my only annoyance is that I find it difficult to remove straps to charge that's all.

Great product , only thing that is wrong is the battery doesn't last for 5 days like it says in the description, you have to charge it every 3 days as it runs out at the end of the 3rd day so i put it on charge whilst i sleep or if im sitting reading at night. Other than that its a fantastic product, it does everything else it says it does. so comfy to wear you forget your wearing it. I have since bought another for my son.

This was a present for my sister birthday. Its a good buy if your on a budget. She has small wrists, and it turns out its a good fit. Big display and easy to use. One down side is if you let it run out of battery it refers back to factory settings.

Very poor Battery as it needs to be charged every 36 hoursReturn process via Hermes is a matter of concern as there has been acknowledgment that the item has been handed in at the required return point but as with Hermes Delivery no auto return text or email

THANK YOU I USE IT ALL DAY

What a load of rubbish,and waste of money have to charge every couple of days