The First Years Microwave Steam Sterilizer lets you get a quick and easy clean for baby bottles, breast pump parts, pacifiers, cups, toys and more. It's quick and easy to use: Just add water and the items to be sterilized and then place in the microwave. The natural steam sterilizes in just minutes with no nasty chemicals needed! The organizer tray is designed to hold different bottle styles and the trees are perfect for bottle nipples, collars or other small pieces. With multiple vents, the steam fully circulates throughout the chamber for a thorough clean.