The attendant may also prepare ingredients, refill beverage dispensers, clean and replenish utensils. Disposable valves may be found in common household items including mini-pump dispensers and aerosol cans. Some Pez dispensers can sell for large amounts as collectibles. Each prisoner transport vehicle has two urinals and two water dispensers. Another solution is to install two toilet paper dispensers. Many liquid soap dispensers operate in this way as well. Pyrofuze foils can be used for e.g. sealing of various dispensers or fire extinguishing systems. Pez candy dispensers portraying him have been developed. Diet Coke from fountain dispensers still contains some saccharin to extend shelf life. The "tunnels" gave access to nesting boxes, food hoppers, and water dispensers. Pez candy dispensers inspired by her have been launched. Early Pez dispensers did not have character heads on them. This trend inspired novelty candy dispensers made to look like steam shovels. Pez dispensers began to be produced in 1997. Other gadgets included chassis-mounted shinbreakers, oil slick dispensers and smoke emitters.