No trades. Not gonna part out the kythera engine. Based gun is an Arcturus M4. The gun is very sturdy and light-weight. The kythera engine is a very reliable HPA system that doesn’t need a battery or an FCU. It’s semi-auto only. Please refer to the Polarstar kythera user manual before you use this gun. Overall, kythera is very easy to operate. The gun comes with the red dot that shown in the picture. You can choose 4 style of reticle patterns. The gun doesn’t have any malfunctions or issues.