Professional Quality, tested to 10,000V and insulated to 1000V AC and 1500V DC for live line working. Manufactured from special tool steel, oil hardened and tempered. Smoothly ground accurate V shaped polished jaw head with locking adjustable screw for setting to the desired diameter. Can be used for solid or stranded wire up to 5mm (10mmsup2;) diameter. Internal screw for one hand adjustment. Heavy insulated handles with slip guards for extra comfort and safety. Display packed.