... -252mm material: W1,W2,W4 W1: all zinc platedW2: bolt, axis,and coupling with zinc plated . others are stainless steelW4: all stainless ... clamps,like Germany type hose clamp ,american clamp, heavy duty clamp, quick clamp, single ear clamp, handle hose clamp,double wire clamp, clamp with rubber and so on.1 ...