Glass water balls! Suitable cartridges for children's guns. Renew your supply with colorful cartridges. Universal balls, fit almost all guns. A large number of balls allows for many hours of fun. The set includes up to 20,000 cartridges. The water cartridges are completely safe, breaking on impact, so they can also be used indoors. Very easy to use. Drop the balls into a container with water. The most common size for the guns is about 7-8 mm. To achieve this size, the balls need to soak for about 3-4 hours. The longer they remain in the water, the more they swell, reaching larger sizes. The balls are shipped in random colors, initially packaged in a plastic container measuring 10.5x8 cm.