Adopt Premium TPU Silicone bands Strap specially designed & crafted for Fibit Charge 3 Bands/Charge 4 Bands/Charger 3 SE Classic Bands and Perfect fit(Note:Tracker is not included). No matter what type of wrist you are, it dose fit well and look nice, Small for 5.5" - 7.1" (14cm-18cm) wrist, Large for 7.1" -9" (18cm-22.86cm) wrist. Premium Waterproof Material: Bands Replacement Compatible with Fitbit Charge 3 / Charge 4 is made of flexible elastomer waterproof material. Sweat and water resistant, lightweight and easy to dry, great choice for swimming etc. Durable premium material can prevents skin from irritation. Very soft and comfortable to wear. Any suggestion will be highly appreciated. We will always stand by you all the time. Available 24/7. 12-MonthHassle free replacement or 100% Full money back if anything unsatisfied. Just contact us via e-mail. We will reply to you ASAP.