MK15 is the main model with 5GHz working band. Being field test and optimized, MK15 can match with HM30 and MK32.
MK15 is the major model. Working frequency is 5 GHz, of which the long range performance is optimized by massive field tests, hardware turning, and software work. The MK15 link is compatible with HM30 and MK32.
MK15E is prepared for specific market in which only 2.4 GHz is allowed. The MK15E link is compatible with MK32E. The MK15E / MK32E link is not compatible with the MK15 / HM30 / MK32 link. The long range performance of MK15E / MK32E is no better than MK15 / HM30 / MK32.
*E does not stand for Enterprise.
MK15E is for specific market( can be used in the countries and areas that approved 2.4GHz)and it can link with MK32E, while it can't matched with MK15,HM30 and MK32. Besides, it can't be compared with MK15 in RC.