Patented button lock design. Tamper evident button lock tab provides product security. No sharp edges, no wasteful strips. RPET plastic provides crystal clear clarity. High clarity and tight lid fit prevents leaks. The button "Loc" tab fastens to the top of the base. If tampered with prior to purchase the BUT-N-LOC® button will not be connected to the tab and a clean hole in the tab will be evident. The engineered tight parameter seal promises a leak resistant experience. Made from 30% post-consumer recycled PET. This container has no external pieces to throw away which makes for safer and smoother handling.