Pliers can be used parallel or perpendicular to the cylinder block. Fine-tooth ratcheting lock allows you to compress bands in small increments. Set works by placing a band around the piston, covering the rings and hooking pliers into the band and squeezing. With the band tightly around piston, insert piston into cylinder and tap lightly with hammer handle to install.
Use the pliers with any band to install pistons from 2-7/8" to 4-3/8" in diameter (73 to 111mm)