There are many different types of closures that perform a variety of functions. Some common types of closures include continuous thread closures (CT), disc top caps, child resistant (CRC) closures, pumps, and sprayers. A CT cap is your basic closure that can be easily sealed and resealed. Disc top caps allow the user to dispense product without having to remove the cap. CRC Caps are child resistant closures designed to keep children from opening the content. Pumps and sprayers allow the user to dispense an equal amount of high viscosity product with each use.