This is an AR-15 barrel nut wrench for 1/2 inch drive torque wrenches, along with a 1-1/8th inch crow's foot for some free float barrel nuts. Be sure to print with many layers of walls and don't hurt yourself.
just good quality ones PLA
20% or more, print with 10-14 layers of wall. Wall is most important for strength
Print with many walls for strength. If need more tolerance, scale up by a little.