From the website: This 20mm strap is made of high-quality black-colored rubber and features a durable Bioceramic loop and a convenient VELCRO® closure ensuring a secure and comfortable fit. The top of the strap features a textured surface that resembles an astronaut suit while the underside resembles craters found on the lunar surface. All straps feature the OMEGA X Swatch, MoonSwatch, and iconic Speedmaster logos and contrasting stitching. Every strap is fitted with a quick release system and comes with a specialized tool for effortless strap replacement. (https://www.swatch.com/en-us/moonswatch-black-black-rubber-acso33013/ACSO33013.html)
It was too large for me but they only give you 14 days to return, so ...