What it is and where it sits in the 39100 series
The 391001808: The PA66/Nylon 6/6 body carries a UL94 V-0 flammability rating — the floor for enclosed panel wiring devices — and operates across -40°C to 105°C, covering the range encountered in unconditioned enclosure environments. The zinc-plated terminal screw over steel gives adequate clamp force for 12-22 AWG without crushing the conductor.
Active production, ROHS3, and sourcing posture
What the 8.00mm pitch means against its series peers
Against the 2-circuit 63 A member (0391002502) at 0.591" (15.00mm) pitch, the gap is even larger — that variant is a power feeder block with a completely different footprint and current class. The 391001808 is its own size in the series: 8 circuits at 8.00mm pitch, 20 A. Match the pitch and circuit count to the BOM position before committing.