Complete Kit to change the nozzle valves mounting to clip on and turn them upright. This consists of several items, the bracket, clips, the clip mount, screws and nuts to hold the clips to the mount. There are 3 main benefits of this kit. 1) The clips make it easier to change a defective valve. 2) With the valves inverted, if an internal diaphragm develops a leak, the reagent is not inclined to go into the electrical part of the valve. This means that the valve driver board will not be shorted out. 3) You can use the better quality valve that we sell for the 3900 and the Northwest Instruments. The improved valve is PN:603-101634.