I built this mod lastnight 1. The tactial switch does not fit perfectly in the spot he said it took me an extra 20 min just to get it where I could push the button in ever so slightly. 2 im not that inclined at building thing but there is hardly room for any of the parts to fit in. 3 If you want to make it a little easier you can put in a drip system like the nicodrip. This works wonders if you dont know where to get the copper tube. Steal one of you womans victoria secret bottles of perfume and use the tube from the pump. All in all it takes a little longer than you would think but be patient it works out in the end