This is the Boom Lift Cylinder on Century Modular 400 & 600 Series light dutywreckers. This includes the 411, 412, 611 and 612 wreckers by MillerIndustries. This lift cylinder has a 4″ bore and a 17.75″ stroke. This cylinderconnects to the subframe and the boom of the wrecker to raise and lower it. Itis sometimes referred to as the Boom Elevation Cylinder. To view the partschematic click on the Brochure tab.Fits: Century Modular 400 & 600 (01/2009 – Current)