The Molex 1727621018 is an 18-circuit, dual-row plug housing from the Mini-Fit Sigma 172762 series, on 4.20 mm pitch. The locking ramp on each side gives an audible, vibration-resistant mate with the matching Mini-Fit Sigma receptacle. A critical detail: contacts are not included.
Glow wire compliance is the feature that separates this housing from standard Mini-Fit Jr. equivalents. The polyamide (nylon) insulation material is formulated to meet the glow-wire ignition test, which is a requirement for household appliance and ITE equipment enclosures. If your assembly does not need glow-wire rating, a standard Mini-Fit Jr. housing will mate physically — the pitch and latch geometry are shared — but the material certification differs. The 105°C upper limit is the housing material rating, not the contact rating — the actual current capacity depends on the crimp terminal and wire gauge used, and must be derated above 85°C per the Mini-Fit Sigma derating curve.
The locking ramp engages a matching ramp on the receptacle side — the latch clicks when fully seated. For a wire-to-board configuration, the receptacle would be the board-mount version (through-hole or surface-mount). The 4.20 mm pitch and 4.70 mm row spacing are shared with the standard Mini-Fit Jr. family, so the physical fit is compatible, but the glow-wire material and Sigma-specific terminal geometry are not identical — always verify the terminal part number against the housing series.