The contacts are gold-plated to 30.0 µin (0.76 µm) on the mating surface, rated for 5 A per circuit at 110 V. The housing is black UL94 V-0 rated thermoplastic. This is a standard board-to-board interconnect — the unshrouded design means it mates with any compatible 2.54 mm pitch female socket or receptacle housing without keying restrictions.
The 0.100" (2.54 mm) pitch is the industry-standard spacing for breadboard-compatible headers — it matches the vast majority of 0.100" female socket strips and IDC receptacles on the market. For a one-time solder-and-forget board-to-wire connection inside a clean enclosure, tin would suffice; for a header that sees periodic reconnections or lives in a humid cabinet, the gold pays for itself in contact reliability.