This Zenith Lumbar Drop Piston-Only contains 1 Drop Piston to repair broken bolts in a NEW Style Zenith 440S or 460S drop. This Zenith Lumbar Drop Piston is made for any zenith table with a SOLID Roll finger style drop ( see Picture). This install kit is a medium install job. Basic mechanical knowledge is needed and is about a 30 minute job total to install.