This is for a set of hold-down clamps for use with T-slot track These clamps are useful in many woodworking and metalworking applications for holding, positioning, and fixturing work Exerts clamping pressure anywhere along the recessed T-track Slides into the T-track and quickly secures with the turn of the knob nut 1 x Complete Clamp Set (Threaded Rod, T-Screw, Knob Nut, Slide Block, Washer, Clamp Panel)