Replacement Depower Main Line complete with Tubing for Navigator Pro Short Throw Control System. For the smoothest sheeting and most reliable form of auto-unwind, you'll see your Navigator Pro Depower Main Line and landing line run inside individual tubes, instead of a single multibore tube. The tubes are made from the highest-quality, durable, wear-resistant TPU and they are stacked front to back for comfortable, one-handed flying.