20 Positions, 2.54 mm Pitch, SMT with Board Lock
The 91618-310ALF: The receptacle accepts either bottom or top entry, and the mated stacking height is specified at 10.81 mm — this is the z-height budget between PCBs in a mezzanine configuration, a dimension that must match the mating header's stack height.
Material and Compliance Essentials
Contact material is phosphor bronze with a gold mating finish (30.0 µinch / 0.76 µm) and tin post finish (78.7 µinch / 2.00 µm) — the gold on the mating face handles the reconnect duty; the tin on the solder tail is compatible with standard SAC reflow profiles.