The RD312 locates lost or hidden metal covers in the street. It is light and simple to use. Gain can be manual or auto. The position is indicated by a varying pitch tone, the highest pitch indicating the maximum response over the target. It is robustly constructed from high impact ABS and aluminium and is weatherpoof to IP54. It weighs 1kg and is easy to use, swiftly locating lost manhole covers, valve boxes, in the street. The RD312 will typically run for 30 hours from a 9v alkaline battery.