Absorption of parallel, angular misalignments and shaft end-play by spring action.Widely used in drive systems for encoders, instrumentation, lead screws, small pumps, feed rollers and anywhere a light to medium duty, torsionally flexible coupling is required.Product Name : Beam Coupling;Features : Screw Type(Coiling Clamping)Shaft Usage : 8mm to 8mm / 0.31 inch to 0.31 inch (5/16 inch to 5/16 inch );Length : 25mm / 0.98 inch Diameter : 18mm / 0.71 inch ;Material : Aluminum AlloyColor : Silver ToneWeight : 13g;Package Content :2 x Beam CouplingOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.