Stainless steel recall strap. Stainless Steel Mounting Plate Optiparts DESCRIPTION Stainless Steel Mounting Plate with Two Holes for Mounting Optimist Hiking Straps and BuoyaSa Bags. Due to a recent rule changed, nylon flat are now allowed in the optimist. Thickness: - Stainless steel: 2 mm - nylon: 4.5 mm