VERTEX 3900-0316 Steel 4-piece T-Slot Clamp Set Kit includes: 4 pc of t-slot Nut, clamping pieces and bolts Special made downward force for holding thin or small work piece Used for milling, drilling and EDM T-slot table Quick and easy setting with hex key wrench Special made downward force for holding thin or small work piece Made of tool steel hardened Used for milling, drilling and EDM with 5/8" T-slot table 4 PC Kit Made of tool steel hardened