The standard 20mm silicon strap for the SRPE31 (Mini Auto Tuna). A comfortable and flexible strap, but not as soft as the new Turtle strap. It has a steel keeper, and a sturdy buckle, both coated in black and with SEIKO engraved. The strap is 20 mm between the lugs, 22 mm against the watch case and also 20 mm at the buckle.
