Sippy Cup - Nuk Sippy Cups

The sippy cup is a spill-proof drinking cup designed for toddlers. It works by way of surface tension that prevents liquid from being spilled even when the cup is upended. The critical element is the sippy top being firmly in place on top of the cup, preventing spills.

The modern Sipster spill-proof sippy cup was invented by Richard Belanger, who licensed the design to Playtex.