Large Gun Cleaning Mat for Rifle Shotgun Pistol, Magnetic Cleaning Pad for All Guns with Organizer Parts Tray and Built-in Ruler, Anti-Slip Thick Workbench Mat for Gun Maintenance. Strong Magnetic & Built-In Ruler: Equipped with 10 embedded magnet clusters to securely hold springs, screws, pins, and small parts in place during disassembly, preventing part loss.