If it needs to be flashy, fancy, creative, playful, unique or just downright cool, Laser Pegs are your go-to! Translucent Laser Pegs construction bricks are like no other construction bricks available (though they are still compatible with all other standard-sized bricks). Each Laser Pegs shape contains an LED that lights up when plugged into the power source (base). Not all bricks in each set are Laser Pegs but the number of Laser Pegs in each set increases with the set size, so you'll always have a well-lit model! Some sets have all clear construction bricks while others have a mixture of clear and color-tinted bricks. The translucent bricks ensure that your finished models light up really well from end to end, especially in low light environments. Pair these sets with the free Laser Pegs app (Apple and Android) for the ultimate experience in imaginative creativity! Sound-Activated Triangle Base and 3D Lite Board require 3 AA batteries, not included, or an AC adaptor (sold separately). Power Base requires 3 AAA batteries, not included. Zippy Do/Mobile Power Base uses LR44 batteries (included).