The jet engine is a rare drop that has a 2% chance of being dropped by MOABS. It can help craft an anti-MOAB unit. Dealers will sell packs of 10-35 for $250 MM for 10, or 875 MM for 35. 25 MM each. Also has the ability to pop 50 layers off of a bloon if placed on one. 32 can craft a propellor plane if some wood is added (100)