Yes you haveto remove the uni-bushing. I then took a .22 cal brass bore cleaning brush and attached it to a cordless drill and cleaned up the inside of the arrow. They work like a champ. There was a couple that I had to lightly sand to get them to fit just right. I have also made some homemade ones that use a wooden dowel inside the arrow with a red thill light that allows me to keep the uni-bushing and G-nock. So far they have worked out suprisingly well but they are not as bright as the Lumenoks.