Stud size and wire range
The 2-34151-3 is the 5/16-stud member of TE's Plasti-Grip ring terminal line, accepting 16-22 AWG wire with a 0.105" to 0.140" insulation diameter range. The tin-plated copper contact is 0.031" thick and the black PVC insulation covers the barrel; the serrated termination on the inner barrel grips the conductor strands during crimping.
Stud-size selection across the Plasti-Grip series
Within the Plasti-Grip series, the 2-34151-3 (5/16 stud) sits between the 2-34150-3 (1/4 stud) and the 2-34152-2 (3/8 stud) — the wire gauge range, thickness, and overall length are shared across the three, so the stud size is the only dimension that changes.