Basically put two broken combat machines into each other to make a working one. Hence why it’s “custom”. Only upgraded that were put into it was a longer inner barrel and better bucking. With all that being said I feel it is a slight step above a beginner gun. Super lightweight and has metal where it is supposed to be. Would love to see someone pick this thing up! Will consider trades for trading or sports cards. Otherwise I am looking to sell Available for any questions!