Proma offers the flexibility of right/left delivery systems with 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. The A6230 includes compass chair bracket and hardware, and vertically adjustable counterbalanced arm with air-actuated lock. Proma units to be mounted on Royal Domain or Alliant chairs can be ordered with an internal umbilical. Please specify internal umbilical when ordering unit. The hygiene compass unit gives great flexibility to the hygiene operatory with the ease of right/left configuration. Everything the hygenist needs is on the swing arm unit head.