12 volt, 4 pole rectifier/regulator combo fits P-series Vespas with frame numbers before VNX 1T 82431 or VSX1T 34627.
The replacement rectifiers we sell have 5 terminals on them. This is confusing, since you're looking for a 4-pole rectifier, but there is just an extra terminal. Just match the colors and you'll be fine.
Connection order (G G R +B L C)