I built this from a Dumas Tug Kit, nice kit with lots of detail. Two SLA batteries provide ballast along with lead weight. Gearing is from an older type model aircraft type. ESC is a marine type, forward, backward drive, big 4" Dumas prop. This tug is back in dry dock for addition of led navigational lighting. The initial build was undertaken while I was battling stage 4 cancer, it keep my mind occupied during chemo and surgery recovery, stayed positive! Model building is very meditative to me, try it if you have't, Have fun. Photos to come once out of dry dock. (Motor: 550 dc) (ESC: Tamar T15) (8/10)