20" (20 inch) Linear Actuator 44 1/4" Extended Length 24 1/4" Compressed Length [From center of Mounting Holes] 12 Volt 20" Extension. 200 Pound (91 Kg) Max Lift. Speed: 12mm /second. 6mm Diameter Mounting holes 20mm Diameter Shaft Wiring included and pre-installed Built-in clutch prevents over-extending and over-compressing.