Feature:1. Easy to operate, labor-saving, fast, smooth and fluent processing surface.2. Safe and reliable, regardless of site or location restrictions.3. Hydraulic hole opener is light, beautiful and easy to carry.4. Can be used for metallurgy, petroleum, chemical, electronics, electrical, marine, machinery and other industries to install and repair the opening of wire and pipe, indicator light, instrument switch, etc.5. Equipped with various of model of different sizes to meet different requirements.How to Use:Operating procedures1. Before the opening of the workpiece to be opened, first drill a 11.5mm guiding hole with a hand drill. Opening a hole of 30 or more requires a 20.5 mm guide hole.2. Screw the piston rod into the screw hole of the piston cylinder, then insert the washer into the piston rod and insert it into the die. Then the piston rod is extended into the guiding hole of the workpiece, and then screwed into the punch, so that the edge of the punch is closely combined with the working surface, and the punch, the workpiece and the die are reliably fixed.3. Close the oil return valve clockwise, then press&n