W2 worm drive hose clips for clamping hose, pipe and ducting onto spigots and barbed or ridged fittings: HVAC and ducting connections, general domestic and agricultural plumbing, and workshop and light industrial hose and pipe fastening. This pack contains 2 clips in the 20-32mm size.W2 construction pairs a stainless steel band and housing with a zinc-plated steel screw. The stainless parts give strong resistance to rust and general weathering compared with a fully galvanised clip; the screw is zinc-plated steel rather than stainless.The worm drive, a screw thread engaging an embossed band 9mm wide and 0.7mm thick, gives fine, even tightening across the full clamping range rather than fixed steps, and the slim band keeps the clip low-profile once fitted.Specification:Clamping range: 20-32mm (0.79-1.26in)Grade: W2Band and housing: stainless steelScrew: zinc-plated steelBand: embossed, 9mm wide, 0.7mm thickMechanism: worm driveRecommended tightening torque: 4.0 NmPack size: 2Choosing a size: each size is named by its closed and fully open clamping diameter, so a 16-25mm clip closes down to 16mm and opens as wide as 25mm. Measure the outer diameter of the hose once it is fitted over its connector, not the hose alone, and choose a size whose clamping range spans it with the screw still short of the end of its travel; if the measurement is close to the top of a clamping range, size up.Fitting: slide the open clip over the hose before pushing the hose fully onto its fitting, then centre the band over the ridged or barbed section. Tighten evenly to around 4.0 Nm, checking the hose has not twisted or ridden up the fitting. Avoid overtightening: past the recommended torque, the band or hose wall is more likely to deform than the seal is to improve.18 sizes are available, from 8-12mm to 190-210mm, in packs of 1, 2, 5 and 10.