Carolina EDC Reviews talk about sights used on the MP5 and UMP series from Heckler & Koch... "Standard Dot front sights use a patent pending glow dot that absorbs light and glows in low light levels before it is dark enough to see the tritium. Green is a great option for low light and has a very bright glow intensity. The surface area of the convex dot increases light absorption, intensifying the charge of the glow properties of the dot.

Wyhaq shows how to install the Ghost Rings to replace the iron sights of the Action Army AAP-01 Gas Blowback Pistol... "This video I show how to install replacement upgrade ghost ring sights for the action army aap-01 gas blowback replica. These are much better iron sights than the stock ones, made out of anodized aluminum rather than the stock polymer. These will increase durability, fit and finish, and just style overall. As well as giving a better sight picture."