To activate your Glow Stick bend it until you hear it crack then shake it up This releases the chemical within the stick immediately it will GLOW lasts 6 to 8 hours Features . Blinkee Fun. Keep Blinking. Pack of 25 Specifications . Color White Red. Diameter 1 75 in . Height 6 0 in . Width 0 75 in . Lanyard Necklace Approx 31 0 in . Dimensions 15 24 x 1 9 cm