Designed to lock on top of ceiling grid after adjacent ceiling tiles are dropped in for holding down acoustical tiles in drafty entranceways and low security areas. After inserting adjacent tiles slide clip over T-bar until base of clip makes contact with tile. To move or remove clip insert a large flat screwdriver in the top of the clip and turn slightly to open mouth of clip enough to free it from T-bar.Universal clip works with most T-bars and ceiling tilesSpring steel teeth hold clip firmly in placeNo tools required to install