Bolen Follower for the STI/SV type magazines. Must use Bolen Springs.
Disclaimer- The followers will work in STI magazines. If you squeeze the last round in and push the follower below the ridges going down the side of the magazine they will most likely fail to feed. To be able to get the maximum rounds in an STI magazine the tubes have to be tuned as is the case with any mag tube you want to get the maximum capacity and maximum reliability. On STI tubes the tuning needs to include removing the step of the ridge. Some tuners will dimple the tube to lengthen the ridge so the follower does not get caught under it. This can be a bigger issue if you use an extended base pad which lets the follower get below the side indention or ridge no matter who makes the tubes. For this reason, and as is the case with most the things we sell, these are not considered a drop in item.