SMV Industries Hydraulic Cylinder, Double Acting, Non-ASAE, Bore Size: 3 in, Rod Diameter: 1-1/4 in, 2500 psi, Stroke Length: 12 in, Retracted Length: 20-1/4 in, BlackBore – piston diameter inside the cylinder tube, the larger bore equals greater lifting forceRod diameter – diameter of the piston or rod, larger diameter equals greater lifting forceStroke – cylinder travel meaning measured dimensions of the extended length of the rod minus the retracted length (measured center pin to center pin)Clevis – most common end type, consisting of two, one on each end, with holes drilled for pins to go thruTie rod – most common in agricultural applications, tie rods are 4 long, threaded bolts, running the length of the cylinder, to provide extra stabilityDual (or double) acting – cylinder works under pressure in a pulling or pushing functionO-ring static seal and piston seal is 2 back up rings plus O-ringRod end cap – 1 NPT port, base end cap – 2 NPT ports