First of all, buy from a reputable dealer. All Comp 4's are phony so far. Aimpoint
hasn't even seen any yet. The most common fake is the Comp M2. The phony one says "Comp M2 4MOA 10338". The problem is that 10338 is the number for a Comp ML2, not an M2. There is also a reoccurring serial number of 240944. The counterfeit three power magnifier
is sold in a plain cardboard box.