R39 ‘HAVANNA’ Genuine Pigskin strap has a cream white seam. When you purchase a RIOS1931 watch strap you are acquiring a high quality crafted product. The combination of traditional, handcrafted perfection while constantly evolving has made the watch straps of RIOS1931 a unique, top quality product. These straps are available from sizes 18 to 20 mm in black, dark brown and tan. Select the size and colour that best suits your needs. Thickness of strap: (approx) 3.5mm to 3.0mm. Cross Section: square. Lug/Buckle Measurements: 18/16mm, 20/18mm, 22/18mm.