Mag well safety flag for your AR15.
These come with an “Empty Chamber” flag that hangs off the bottom and we have an indicator that shows through the open slide that the bolt is open.
The raised arrow makes it easy to know which way to insert it.
These can also be used in a vise to hold the rifle for cleaning or other work being done. Don't torque a barrel nut using it but general cleaning and such can easily be done.
**WARNING! These are 3d printed, plastic. They are NOT a bolt stop/catch. You cannot install them and slam your bolt forward on them, the chamber indicator cannot withstand repeated abuse of a bolt being slammed forward.
When finished and you make your weapon safe, install the magwell/chamber safety and either keep the bolt locked back or GENTLY ride the charging handle forward to rest against the safety device.