View this release
Alternative links
These files have not been tested or printed yet, but they should be dimensionally correct because they were built around the McMaster Carr step files for the required hardware. Only slight fitment/sanding/deburring should be needed. This was intended to solve the issue of floppy, dangly, noisey Quick Release Pin pull rings on printed lower receivers like the AR15/AR9 variatons. If your receiver is different than the UBAR in any way, make sure you choose the correct cross pin length if you intend to use these for other lowers. Measure twice. If there is enough clearance these knobs should work on other lowers with the correct length pin for that lower as well. Instructions are included in the Zip.