LED Light Up Multi Color Tunnel Drink Coaster Light Up Tunnel Coasters have four light-up functions including a rapid-flashing, slow color-changing, still light, and individual flashing colors! Includes 2 replaceable CR2032 Batteries. Press the clear button located on the back of the coaster to activate and change the light settings. LED Colors: Blue, Red, Jade Diameter: 3.75 in. , 9.52 cm.