The VideoRay Radiation Detector mounts easily to the bottom of either the Pro 3 or Pro 4 ROV systems and utilizes the 9-pin accessory port. The unit is very sensitive to gamma radiation and high energy X-Rays. The sensor is not designed to detect alpha and beta particles since the tube is mounted inside a pressure housing. The RM-60 radiation monitor perceives radiation passing through 1.4" thick black Acetal (Delrin) wall. Gamma Sensitivity 10 Kev. Cesium Calibration Tube calibrated to Cesium 137 +/- 5% (MIL-STD-45662). Software digitally locked to tube. Size 10.55" x 3.50" x 3.25" with tube-end visible from VideoRay's camera.