Heavy Duty Lug Crimping Tool, 6 AWG to 4 0 AWG, Black ORS NASCO nuts and studs to prevent nuts and studs to prevent loosening due to vibration Permanently locks assemblies which must not come loose Product works on all metals Features Rhino Tex™ synthetic leather palm Kontour Index™ design seam on back of index finger Exclusive Caiman® raised pull patch and pulse protector AirMesh™ ultra breathable back provides ultimate comfort and support Pinch'd Tip™ fingers for optimum sensitivity Heavy duty steel body with double slide support for rigidity Durable spring loaded mechanism holds terminal lug in place Easy to read scale on both sides of drive punch Wide base for stability