Hydro means water, and that's just what makes the beads and glitter in these bracelets float and sparkle. If you're looking for a great summer birthday party favor, this is it. Just buy extra supplies (the ones listed here will make three bracelets).
To make each bracelet, cut an 8-inch-long piece from the 1/4-inch tubing and cut a 1-inch length from the 3/8-inch tubing (for a fastener). Slide both ends of the 8-inch tube into the fastener, as shown, and have your child try on the bracelet for fit. If it's too big, take it apart and trim it to size, remembering that it will need to slip over her hand.
Remove one end of the bracelet from the fastener. Use a finger to stopper one end while your child drops in tiny beads or pieces of glitter -- or anything she likes that fits in the tube and can be submerged in water.
When she's done, slowly fill the tube with water, leaving several inches of air so it has room to move. Carefully slide the free end into the fastener as far as it will go. This should create a snug fit that won't come undone without a good tug.