These clamps provide 360° radial compression with no steps or gaps on inner circumference. Ear design provides spring action during vibration and thermocycling conditions. Chromium-nickel stainless steel has a high strength-to-weight ratio. Oetiker Stepless Ear Clamps are made of UNS S30400 or DIN 1.4301 stainless steel. Excellent corrosion resistance in both aqueous and atmospheric environments. Selecting the correct size: Select the nominal size nearest to, but always larger than the outside diameter of the material to be clamped. The outside diameter should be determined with connection fully assembled. Note: multiple barb fittings may require the use of a larger clamp size than single barb fittings - when closed the ear width should be reduced by at least 40% when pinched. Use the jaw pincers to tighten down the clamps.