Features 1、[EASY INSTALLATION] Just install the base on the bottom of the emergency stop switch to install, no need to disassemble. 2、[MULTIPLE USAGES] When you do not need to lock it, you can only keep the base without affecting the use, or you can lock the base. 3、[STANDARD SIZES] With standard bottom mounting hole diameter, suitable for all kinds of standard knob switches. 4、[PC MATERIAL] Made of excellent PC material, wear and corrosion resistance, with dustproof effect. 5、[WIDE APPLICATIONS] Suitable for industrial, chemical, electric power, petroleum, coal, flammable and explosive places. Specification Item Type: Round Switch Guard Cover Model: BS-03 Material: PC Uses: Applicable scenarios, suitable for industrial, chemical, electric power, petroleum, coal, flammable and explosive places Bottom Hole Diameter of the Protective Cover: Approx. 46mm / 1.8in Bottom Hole Diameter of the Semicircle Fitting: Approx. 30.5mm / 1.2in Bottom Hole Diameter of the Circular Fitting: Approx. 22mm / 0.9in Package List 1 x Protective Cover 1 x Circular Fitting 1 x Semicircle Fitting 1 x Double Side Sticker