I printed this illuminated sight because I was searching for a low budget, light weight and cheap night sight for quite some time but didn't find one. A red dot is too chunky for a handgun in my opinion and light is illegal in my country and draws attention to the shooter. This sight is basically a light stick holder that goes behind the normal front sight of the gun and works like tritium night sights but at a much lower price and without the danger of radiation (which is minuscle anyway). I did not design a rear sight because I don't need one myself and didn't want to replace my original rear sight. Also in many guns the rear sight is adjustable. Therefore its bad to replace it. If you wonder about the problem, that there is an illuminated dot at the front of your gun with this sight that draws "enemy" attention there is an easy solution for that: Put a ball of duct tape in the front tube of the sight after inserting the glow stick but don't print it closed or glue it closed because otherwise you can't remove the glow stick anymore and need to replace the whole sight after it is used up. If you don't like the faint glow the sight emits to the side print it either out of black ABS or spray paint it. Smoothening the sight with sand paper and adding filler and spray paint to it is recommended if you mount it to a real gun, because otherwise it looks pretty crappy and cheap. Post processing: After printing the sight I drilled its hole to 4,5mm and sanded its floor plate to have an even surface to glue it to the gun and to be able to insert the glow stick easily. Fastening: I glued the sight to the gun with superglue. Double sided adhesive tape might work, too. But I doubt it will hold out on a real gun or after several shots. Heat can also be a problem. Compatibillity: This sight works with any normal green glow stick with a size of 4mm x 4mm x 39mm. They last for about 6 to 12 hours and can be bought at fishing stores. Legallity: This sight is completely legal in Germany as far as i know.