Front and rear view of air search radar mattress. This is the standard air search radar of the Imperial Japanese Navy. Its max detection range was 100 km/62 miles for groups of aircraft and 70 km/44 miles for single aircraft. The antenna weight 840 kg/1,851 lb. Two sets of transmitting and receiving array consisting of 10 mm copper bars are located inside the antenna. The white cone shape objects are the ceramic insulators on which the bars are attached. The whole mattress normally rotate on the cyclical device on which they site on.