The Blazers only come in 2" length. I have weighed several and they all seem to be between 5.5 and 5.9 grains each. I mount them with a right helical clamp and a 2-3 degree offset. I dont know if they really get a true helical twist to them but that was the clamp I had and didn't want to spend another $28 for the straight clamp. They work fine. I have used 3 vanes on all the arrows I have previously built but I am curently testing out some 4 vane arrows with nice results. The 4 vanes appear to stabilize the arrow faster, uh that would make sense, huh? So far my groups with 4 vaned arrows are 1" higher at 20 yards. I will go out to the range tomorrow and test them out to 30, 40 and maybe 50 yards if I get the time. At this time, I would say to go for 4 vanes if you are getting new arrows made. I will let you know my results tomorrow.