Look at it from the back. There will be two vents on at each end. The one on the left side will have some silver fins right against the grate. This is your primary heat pipe condensor. Now take a look at the other side, if you see fins right on the other side of the grate, identical to the other side, you have a dual pipe. If the fins are set further back, maybe 3/4 of an inch as opposed to the other side, you have a single pipe. The recessed fins are those of the CPU heat pipe. e1705s come with single pipe GS's. M1710s come with dual pipe GTX's or GS's.