I took the window off the led The k75 as a host is light weight with a huge reflector so i will put the 2mm2 osram and led4power driver in it, see how it goes. The astrolux battery tube fits and I have changed the battery carrier to 4s which fit the acebeam tube. However the acebeam carriers dont fit in the astrolux tube I am waiting for more leds so i will do a test with Q8 driver and the sbt-90 from the k75. I have a host knocked up for test. The k75 driver and led will go in a aspheric with a collar and 150mm lens with 177mmFL. i have done some tests without the collar and and 145mm lens, looks like it will be alright