The clamps are built with Stainless Steel 6-32NC Socket Head Cap Screws (SHCS) requiring 7/64 tool.
The A-250-SJC-5.0 is designed for Code 250 rail that has a flange width from 4.5mm-5.5mm. That includes the Llagas Creek Code 215 and Code 250 rail sold in this store.
This is an Aluminum (Silver) railclamp.
Price shown is per each railclamp.