R133 "JUST"- Hightech Material NYTECH strap, water resistant, with the stitching matching the colour of the strap. When you purchase a RIOS1931 watch strap you are acquiring a high quality craft product. The combination of traditional , handcrafted perfection while constantly evolving has made the watch straps of RIOS1931 a unique, top quality product. R133 "JUST" watch straps are available from 18 to 24mm, in black only. Thickness of strap: (approx) 7.0 mm to 3.0 mm. Cross Section: round. Select the size that best suits your needs. Lug/Buckle Measurements: 18/16mm, 20/18mm, 22/20mm, 24/22mm.