I'm shooting 3-D selects with easton super noks. The problem I'm having is this arrow is really lite for hunting. So I attach a 10" weight tube to the nok and insert it as one piece into the arrow. I do this for increased weight of 30 grains to give me 6 gr. per lb. which I prefer for broad heads. I know. Why not just change arrows? Cause I'm pig headed and just like the spec's of these arrows. and they flew great for me for 3-d. Well after shooting an arrow about 20 times w/this set-up the super nok comes lose and comes out at impack. My solution is use the uni nok sys. What size do I use for my 200 3-d selects. 60's or 71's? I tried a 60 and it seemd a little lose. I know this is more info then you needed for the question but hunting season is close and I'm going into rutt. lol Thanks. Jerry