Recommend screw size for installation is 4mm (0.16 ") x7mm (0.28 The toggle clamps is easy installation, just fix with screws The installation distance is, Even you install it little bit away and close, you could adjust the screw and make tight and loose Push Pull toggle Clamps, allows you to hold workpiece in a vertical position; can movable base Can be used in the metal working industry when drilling, welding, bending, testing as well as in the wood and industry in glueing, drilling Works well for different temperature environment, indoor and outdoor Oil and stain resistant cover handle for easy, safe and comfortable, Manufacturer: Msioytog