What it is and where it fits
The 387800105: Wire range is 14-22 AWG, and the top termination accepts screws that clamp the conductor directly. The terminal screw finish is zinc clear chromate on steel — adequate for most indoor industrial environments, though for corrosive or outdoor panel locations a nickel-plated alternative in the same series would be worth checking.
How it compares to the Eurostyle 39100 peers
The listed peers (0391002012 and 0391002502) are Eurostyle terminal strips — a different housing and termination system, not a direct cross. The 0391002012 runs 0.394" (10.00mm) pitch at 30 A / 600 V across 12 circuits; the 0391002502 goes to 0.591" (15.00mm) pitch at 63 A / 600 V with only 2 circuits. Both are white enclosed-body blocks where the Beau 387800105 is a black flange-mount barrier strip with a 0.438" pitch and 15 A ceiling — the mounting footprint, body style, and current/voltage ratings diverge enough that neither peer drops into the same panel cutout without rework.