Material:Aluminum Alloy Color:Silvery Packing List:2PC/SET Also ideal for clamping jigs & fixtures. This T-Track is specially designed for CNC 3018 series. It can provide you with a heavy duty and reliable solution to keeping your T-Track or T-slot work pieces in place. Puts clamping pressure anywhere along the flush-mounted T-Slot T-Track Slides into T-Track & quickly secures with the turn of the hand knob. This is for a set of new Hold Down Clamps for use with T-Slot track. These clamps are useful in many woodworking & metalworking applications for work holding, positioning, and fixturing. The star knob gives you full-range control. This makes adjusting, tightening and securing your material a breeze.