MATERIAL: The hold down clamp kit is constructed of Zinc-Aluminum Alloy for durability and wear resistance. DIMENSIONS: This clamp is 50mm length x 20mm width x 56mm height. DESIGN: The size of the slot block of the clamp is designed for 3018 series CNC router. It can also fit ALL other 3018 series desktop CNC router perfectly. FEATURE: The clamp accommodates material up to 30mm and holds it firmly in position. It can hold most of the material for desktop CNC router machines. VERSATILITY: This clamp provides exceptional clamping action for your universal t-track system configurations and assemblies. It is ideal for work holding, positioning, and fixturing for woodworking or metalworking, including routers, drill presses, CNC, table saws, jigs, panels, vertical mills, and more. Specification: Material: Zinc-Aluminum Alloy. Package includes:4 x Mini T-track Hold Down Clamps.