On general aviation aircraft, it's often difficult to see your wingtip navigation lights from the cockpit because of the angle. To solve this problem, aircraft manufacturers sometimes design a small piece of clear plastic behind the wingtip lights to let a small amount of the light reflect back to the pilot. This provides added safety by allowing the pilot to verify that the external lights are on and actually working (and thus visible to other aircraft). This design should be compatible with most general aviation aircraft since they share a very similar hole layout pattern, particularly Piper, Cessna, and Mooney aircraft. Small scraps of material necessary for this project can usually be found for $1 or less. Factory-made OEM replacements can be $100 or more for a pair of these reflectors, which can be broken easily, making this a fun and affordable project if you have access to the cutting equipment. For certified aircraft, the FAA allows the fabrication of owner- or operator-produced parts that are designed through reverse engineering of a factory part. Your A&P will need to sign your aircraft logbook to approve installation of this component as a "minor" alteration as being airworthy. For experimental aircraft, the owner can make the determination as to airworthiness. You should make two copies of this, one for each wing tip for your plane. Recommended material: clear 1/8 inch acrylic, cut with laser cutter. Alternative material: clear 1/8 inch polycarbonate, cut with CNC milling (do not use laser cutter with polycarbonate due to fume toxicity).