The 280610-1: That pitch is a standard for moderate-current board-to-board or cable interconnects — the spacing gives each pin room to carry current without crowding the board trace fan-out.
Board Fit and Termination — Through-Hole, Single Row
The header mounts through hole with solder tails 0.130 in (3.30 mm) long. Overall contact length is 0.642 in (16.30 mm), with a mating pin length of 0.394 in (10.00 mm) — enough reach to engage a standard receptacle housing. The 3.96 mm pitch means the board footprint needs a 0.156 in hole spacing. Single-row layout keeps the board edge clean and the routing simple — no second-row trace squeeze.