To activate your Rainbow Spiral Bangle Flashing Bracelets, slide the tiny switch on the battery pack. Slow morphing rainbow LED followed by gentle flashing is easy on the eyes. Dimensions: Diameter: 3.25 in. Depth: 0.4 in. LED Colors: 1 Blue, 1 Jade, 1 Red Rainbow Spiral Bangle Bracelets come ready to use with 3 replaceable AG3 Batteries. TO CHANGE: remove the plastic connector where batteries are located – pops out easy. Use a small screwdriver to wedge the battery cover off; located on opposite side of on/off switch. Before putting in the replacement batteries, notice which way the old batteries are facing. Insert the replacement batteries in same direction, click the battery cover back on & you’re ready for another night out.