Simply remove your old band, thread the band's attachment onto your for Whoop device, and hook the clasp to your U-shaped bracket. It's a hassle-free process for immediate use. Premium Quality Material: Constructed from high-quality, breathable nylon material, our replacement bands are engineered to provide unparalleled comfort and durability. They can withstand even the most intense workouts, ensuring they won't let you down. Colour: Black Material: Nylon+ high bomb silk Package Contents: 2 x Chest belt Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.