When I tried them, they were pretty crappy and didn't work. They didn't work for several of the other guys I know either. The problem was that when you shot your bow and they turned on, they would immediately turn off when coming off the string. I had to slow motion video my bow to see that they did in fact turn on but then immediately turned off when leaving the string because. They just pulled out a little bit because of the fit on the serving. I already have a slightly smaller center serving diameter than most people because I like a little looser nock fit but they still didn't work for me and I wasn't about to go smaller and ruin my nock fit for every other nock I own, especially when my Lumenocks work and fit just fine for me.
