Board-layout fit: 6.35 mm pitch and the four-wall shroud
The 641966-1: The 0.250" (6.35 mm) pitch sets the PCB hole pattern — a 3-position single-row header needs three plated through-holes on that spacing, with the four-wall shroud adding a keep-out zone around the insulator body. The shroud is 0.550" (13.97 mm) tall from the board surface; the solder tails extend 0.155" (3.94 mm) below the board, so the total z-height above the board plus the tail length determines clearance under the board.
Current and voltage ceiling for the circuit
The operating range is -40°C to 105°C; above 105°C the nylon insulator and tin plating begin to degrade, so derate current if the ambient inside the enclosure exceeds that.