When I first saw a 23, I thought holy shit this is going to hurt, I had the 1 inch ones and it didn't hurt a bit. I then got the 1 1/2 and though fuck me these are long but liked it better. I then tried 25's, 27's, slin pins and felt they caused lumps, the gear didn't feel like it went in right, pushing so hard to get it out. It was a pain. I went back to 1 1/2" 23's and love them. Easiest way to inject.