The Red Noir Pembroke Silver and Rope Eyewear Strap was both designed and skilfully handcrafted completely in Great Britain. Combining British craft manufacturing with a discerning modern-minimalist style this ANCHOR & CREW eyewear strap features: 3mm diameter performance Marine Grade polyester and nylon rope (GB) Solid .925 sterling silver divider pulley (GB) This eyewear strap is one size fits all with the rope able to extend or tighten to suit your ear-to-back length. To take the eyewear strap on or off your glasses simply tighten the knots around the glasses’ temples (arms) and to adjust the strap’s length simply push or pull the dividing slider along the rope.