The 5.00 mm pitch and 2 positions define the board footprint — two holes at 5.00 mm centres, with the 0.138" (3.50 mm) post length for the solder tail. The 20 A per contact rating is the headline number, but the limiting factor in practice is the temperature rise in the housing at full load; the -40°C to 120°C operating range and UL94 V-0 nylon housing keep it within spec for equipment inside an enclosure. The glow wire compliant feature (per) means this header can be specified in appliance and lighting applications where IEC 60335-1 glow wire testing is required.
It is ROHS3 compliant. For a BOM line that needs a 2-position, 5.00 mm pitch power header, this is a stable, in-production choice.