Fitbit Classic bracelet

The classic strap is made of a flexible, durable elastomer material, similar to the material used for many sports watches, and includes a buckle and surgical stainless steel. Classic Accessories straps are tested to withstand up to 5 ATM, i.e. they are sweat, rain and splash water resistant, but should not be worn while swimming. We recommend that you remove the tracker before showering, as it is best for your skin if the strap remains dry and clean.
If the classic strap gets wet or if you sweat while wearing it, take it off and make sure that the strap is completely dry before you put it back on. Take the strap off occasionally to give your wrist a rest. Size S fits wrists with a circumference of 14 - 17cm. Size L fits wrists with a circumference of 17 - 20.5cm.