This is a very easy crossbow mod that just about anyone can do. All you need is a stock crossbow, 1 foot of 17/32 brass tubing and some stefans. First you load a dart into the end of the 17/32, and then you push the 17/32 into the crossbow. Then you prime the crossbow and shoot. Since the end of the barrel of the crossbow is thinner than the front of the barrel, it makes a snug fit. The ranges are about 50-60 feet flat and 70 feet angled.