If you have a Porsche 928 with 8″ H4 headlights and two of these...
An H4 LED bulb and driver — sold under different brands with only minor cosmetic variations — with the following key characteristics:
barrel of the bulb at the heatsink-side of the three-tab flange measures 22.0 mm ± 0.2 mm in diameter and extends approximately 15 mm from the flange and slightly chamfered for about 4 mm before the threaded, narrower part of the barrel
LED driver module can be disconnected from the bulb (electrical connector unscrews and disconnects)
removable heatsink can be unscrewed and will pass over the LED driver module connector
LED driver module has M3 × 0.5 mm screws fastening the bottom cover, spaced at 56.0 mm ± 0.1 mm along the long edge
We do not sell this or any other H4 LED bulb; you must obtain them elsewhere.
... and want a cap and driver module attachment solution that looks like this: