... satin finish. 16-gauge (1.6mm), 1-1/4" (30mm) square tubing and 18-gauge (1.2mm), 1 ... " (25mm) diameter seamless tubing.Mounting Flanges (2) — 18-8 S, ... three mounting screw holes.Baseplate — 18-8 S, type-304, heavy-gauge stainless steel.Spring — 17-7 ... 18-8 S, type-304, 16-gauge (1.6mm) stainless steel with satin finish. TOP SIZE: 26" 28" 30" 32" available. Series ...