What size fits a 2016 aluminum?  How about an 1820 aluminum?  Chad

Sorry Chad, I can't help you on Aluminum. Just too many nocks to stock as it is with the carbons. Decided not to fool with aluminum from the git go.
BigJim

Chad,

Looks like they do fit 'some' aluminums.  A couple sizes of x7, xx75 and xx78 but not many are listed in the sizing chart  http://www.nockturnal.com/size-chart/.   Also take a look at their Universal Nock that comes with different bushings.  OR call the company.

I don't like lighted nocks.  

I took an ill advised shot through some brush.  The nock showed how the arrow was deflected, and the broadhead was driven into the base of a tree.

Every time I looked that direction for the rest of the day, that d%#m red nock kept reminding me of my stupidity.    

I shot 2 deer Nov 10th, arrows stayed in deer but kicked out along the blood trail somewhere. I didnt find them(arrows).  A few days later I got a call from a friend that he found them both in the dark coming out. Love them

Learned this fall that on a pass through they're great at telling you where the deer was...