The product is a set of four Fitbit Charge HR wireless activity wristbands/watches in black color. They are small in size, made of plastic, and suitable for indoor/outdoor use. The device is compatible with iOS and Android operating systems and provides measurements such as heart rate, speed, time, and calories. It also features wireless Bluetooth connectivity, GPS, and is water-resistant. The device is rechargeable and has a variety of features such as a stopwatch, exercise log, and sleep tracker. It is suitable for gym and training, yoga, and running and jogging. No Chargers - All 4 work properly