Lightweight and comfortable silicone band. I'm a woman with very thin wrists, so I believe I chose a small size, probably S/M. As a bonus, I'll include two bands that fasten with Velcro, which I no longer use. The Velcro on the bonus bands isn't as strong anymore, but they are offered as a bonus, so please understand that they are sold as-is. All three are Apple original bands, for 39/40/41mm. I think I used the silicone band for a maximum of 2 or 3 months. I used the Velcro-type bands for several years. - Color: Light Gray - Type: Silicone Band - Color: Red and Blue - Type: Woven Nylon Band - Brand: Nike Thank you for looking.