Set includes the following separate gauges combined into the four-cavity housing: Compass, Tank pressure gauge with separate water temperature readout built in, Depth gauge and Down timer which probably needs a new battery. All other gauges work fine. Line with good O Ring threads right into one of your high pressure first stage regulator ports. The compass, depth and down timer gauges can be removed to insert other gauges for customization. Will ship within the U.S. for an additional $15. otherwise pick up available.