It seems that they are quite a bit longer than the aw imr's? I finally got a couple of the button top variety. They work alright and they certainly go a very long time. I just found that I can't fully screw on the end cap, well maybe I could but I'm not comfortable doing it as it seems as if it would be pressing very hard against the top connector if I did so. Anyone else find this to be true, and if so what did you do to accommodate the increased length?