Black Rosette Clamping Knob, 5/16-18 Threads. Quantity 4 pcs. Length of threads Only 2” Long. partially threaded. Thread Material is stainless steel - anti-rust and anti-corrosion These larger knobs are for added leverage aiding in the tightening and untightening of the Clamping Thumb Screw. Sometimes you need just a little more holding power with the ease of the Clamping Thumb Screw. “A” = 1-1/2”. “B” = 1/2”. C=1/2 “L” =. Strong and durable. UPC 809555080396 Brand LocEzy Color Black Model HDS-516-RO2-4BL Head Type Rosette Size Name 2 Metal Type Stainless Steel Unit Count 4.0 Count Part Number HDS-516-RO2-4BL Thread Size 5/16-18 Thread Type Unc Drive System Thumb Finish Types Uncoated Grade Rating Premium Manufacturer HDsmallPARTS Thread Class 2B Thread Style Right Hand Fastener Size 5/16 Fastener Type Thumb Screw Material Type Stainless Steel Exterior Finish Stainless Steel Thread Coverage Partially Threaded Number of Pieces 4 Screw Head Style Round Screw Point Style Flat Point Warranty Description 30 day returns Set Screw Thread Type Unified National Coarse (UNC)