Rob Allen 5/8" (16mm) Blue on Amber Speargun Rubber/Power Band Material--50 FEET Quantity 5/8" or 16mm Premium Speargun Rubber Crossectional Dimensions: Outside Dia. 5/8 in(15.8mm), Inside Dia. 1/8 in(3.2mm), Wall Thickness 1/4 in(6.4mm) Famous Rob Allen Quality and Power Protective Outer Layer Tolerance: The manufacturer's diameter tolerance is +/- 0.02 in