This a 52mm diameter mechanical turbo boost gauge from VDO's Vision range. Featuring trioptic technology to give superb night time illumination and pointer lighting. As standard the illumination is white, but can be changed to red or green by fitting one of the supplied diffusers. The black dial face displays a scale of 0-3 Bar. The gauge is supplied with a 5' PVC pressure pipe and 1/8"NPT bush fitting.