Equipped with a robotic arm and search light to harvest sea cucumbers in mariculture, but can also be deployed for maintenance of underwater structures in harbors/ports.[5] Several foreign countries including North Korea have shown interests and invited the developer to their respective countries to develop similar midget subs, including possible military applications.[6] Aurora class two-people midget submarine: successor of Aurora class one-person midget sub, with dimension increased to 7 m x 2 m x 2 m from the original 3.6 m x 1.8 m x 1.2 m, and the maximum depth is increased to 30 m, while speed and endurance remained the same.[7] Crew is increased to two.[8] As with its predecessor, this two-people version also attracted attention of prospective foreign interests.[6] Tao Xiangli class midget submarine: This homemade submarine is developed by Mr. Tao Xiangli (陶相礼, 1974 -).[9] To reduce developmental cost, Mr. Tao uses 2nd hand material whenever it was possible, and as result, it only took ¥ 30,000 (US$4,385) to complete his first boat.[10] For example,the hull is constructed of five used fuel tanks.[11] Tao's submarine weighs 800 kg (1,764 lb) and is 6.5 meters (21 feet) long, with a cramped interior that fits one person and features pressure gauges, monitoring cameras and, of course, an oxygen supply.[12] The electrically powered midget sub shapes like a torpedo with a conning tower, and is able to dive to 10 meter depth.[13] Mr. Tao confirmed that he has received funds for further development, which would enable the next midget sub planned to build to dive to a depth of 50 meters.[14]