What it is
The Beau 38721 series 387217303 is a single-row, 3-circuit barrier strip rated 20 A per circuit at 300 V with a 0.375" (9.53 mm) pitch and a black glass-filled PBT housing rated UL94 V-0. The 12-22 AWG wire gauge range means the 20 A per circuit rating is usable across the full range, but the thermal margin narrows at 22 AWG — a 22 AWG conductor carrying 20 A continuously at 100 °C ambient approaches the insulation ceiling faster than the same current on 12 AWG. Operating range spans -40 °C to 100 °C, which covers the thermal envelope of most enclosed panel environments without derating the current below the listed 20 A.
Termination
Top termination uses screws with a captive plate — the plate holds the wire firmly against the bus bar under vibration, so field wiring does not loosen over thermal cycling the way a loose screw clamp can. Bottom termination accepts a 0.187" insulated quick-connect tab, which is the standard disconnect size used for panel instrumentation and control-circuit take-offs — useful for circuits that need to be broken without unwiring the screw stack.
Panel mounting
Flange mounting with three mounting holes and a 2-wall dual barrier design gives solid panel anchoring without a DIN rail foot — this is a direct-panel or enclosure-backplane part, not a rail-mount terminal block.