The A6310 traditional over the patient delivery is designed to meet the demands of today's technology. Please specify left- or right-handed model; manufacturer and model number of chair; and manufacturer and model of light (if required). Proma units to be mounted on Royal Domain and Alliant chairs can be ordered with an internal umbilical when ordering. The Proma unit has the proven reliability of a pinch valve block system. The pinch valve system is so reliable that Proma gives a lifetime warranty on the whole block system.