LEGO products use several light types: small LED keychain lights (LEDs often in the feet or bottom with an on/off switch in the chest), integrated LEGO light bricks in display sets that activate when you press a central column (sometimes allowing directional adjustment by rotating the column), and lights built into toy trains and action bricks that trigger lights and sounds.
Across the results the products use several battery types: 4 AAA alkaline (train set), 2 LR41 silver-oxide (light brick display), 2 CR2025 lithium (many keychain lights), and 2 CR1225 3V (one keychain variant).
Control methods vary by product: keychain lights usually have an on/off switch in the chest, integrated light bricks in display sets activate by pressing a center column (and some let you direct the beam by rotating that column), and certain train sets use action bricks and app features to trigger lights and sounds.
Most keychain lights are described as ABS plastic. At least one listing or review highlights a rubber-style banana keychain construction, so both ABS plastic and rubber-style materials appear in the available descriptions.
LEGO keychain lights are designed for portability: they include a metal key ring for attachment and the figures typically measure around 2 to 3 inches tall, making them easy to attach to backpacks or keys.
Many keychain models place LEDs in the feet, while at least one variant uses an LED mounted in the bottom of the figure.
Reviews describe the brightness as moderate—suitable for reading or finding items in dim light but not very strong. Product descriptions suggest the lights are useful in low-light situations rather than as powerful flashlights.
Building sets use integrated LEGO light bricks that can be activated and sometimes directed (for example, by pressing and rotating a column in a display lantern). Some playsets also include action bricks and companion app interactions to trigger lights and sounds—such as lighting effects in toy trains.
