Lightpen for the Vectrex. Uses an OPL-801C phototransistor mounted to a 1.5mm x ~8mm circuit board OR can be directly wired with heat shrink and cable placed into a rigid drinking straw for support. If using a perfboard, use Bud Industries DMB-4769-CB or perfboard cut to size and bevel the two corners on the end that you mount the transistor to and cut/break the other end of the perfboard at the mounting holes and sand/file clean (if using the Bud board). Print the pen body with supports as there is a retaining ring in the base that locks the end cap into place. Have your z-seam aligned on the pen body and dust cap for best aesthetics. You may have to tweak the size for the dust cap and end cap for proper fitment depending on your printer. Two strain reliefs are included: a 4mm for using off the shelf 3 conductor 28AWG cable or a 4.5mm for using a repurposed Sega Genesis/Mega Drive controller cord. Cable glues into the strain relief. Leave ~1/2" (13mm) of cable jacket on the inside of the end cap.