The 95278-801-20: The solder tails are tin-lead (150.0 µinch), which means reflow profiles should follow tin-lead solder paste recommendations.
Surface mount termination with all 20 positions loaded. The row spacing is also 0.100" (2.54 mm), so the overall footprint is a 2×10 grid on a 0.100-inch pitch. Mating length is 0.232" (5.90 mm) — enough to engage a standard 0.100-inch pitch socket or IDC receptacle. The unshrouded header mates with any 0.100-inch pitch female socket that accepts a 0.025-inch square pin. No keying or polarization — orientation is set by the board layout.