Some building sets use a LEGO light brick that is activated by pressing or rotating a central column. Keychain lights use LEDs (often located in the feet) and are turned on or off with a small switch in the chest.
Keychain lights are compact—commonly around 2 to 3.5 inches tall—and include a metal key ring for easy attachment to keys, backpacks, or bags.
Most keychain lights are made from ABS plastic. At least one model uses a rubber construction that’s noted for easier battery access.
Keychain lights include a metal key ring for attaching to keys, backpacks, or bags. The building set is a display model with a removable top and an upper tier that can be removed to access and showcase the scene.
Product descriptions indicate the keychain lights are useful in dimly lit areas. However, at least one user review describes the brightness as moderate rather than very strong, so they may not replace a high-power flashlight.