A vintage 1960s quality rubber watch strap, the ends on this are approx. 19mm – they measure around 18.6-18.9mm depending on angle and pressure applied with a caliper. The buckle is 16mm on this and comes supplied with a generic stainless steel one. Length of the strap is 11.5cm 7cm (not including buckle) This is a quality strap and I have sold many before on Ebay to buyers with divers watches, some have managed to squeeze these on to 18mm lugs. The rubber is maluable and quite thick. Unsure of manufacturer, but the ends are signed L/419 on the reverse.