HDsmallPARTS/LocEzy, Rosette Clamping Knob, ¼”-20 Threads. Quantity 10pcs. 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”. “L” = Length of Threads Only - 1-1/2” Long. Partially Threaded. Thread Material is Stainless Steel - anti-rust and anti-corrosion. Strong and durable. Smoother Threading action than Zink Coated Bolts. (Anodized Black Alloy will rust) Manufactured and Shipped from the USA. Order Before 2:00 pm EST to ship the same day. Comes in 2”, 1-1/2”, 1”, 7/8”, 3/4”, 5/8”, 1/2”, 3/8”. If you don’t see a size Clamping Thumb Screw needed, inquire through the Amazon contact seller page and I will do my best to put together what you need and list it.