Patent ID: 8037847

Claim:
An improved closure system for a cage containing laboratory animals, the cage comprising a top and a base, air inlet and outlet valves, a filter retainer in the top, wherein at a boundary between the top and the base the system comprises: at an edge in one side of the boundary a substantially U-shaped housing towards the outside of the edge; a first gasket housed substantially within the substantially U-shaped housing in the edge, the first gasket having a lip projecting out of the edge, the lip in an unengaged position remains within boundaries defined by and extending out from opposing inner sides of the substantially U-shaped housing and in an engaged position has a length for an end of the lip to engage with and bend with contact from one of a side rim of the top and a side of the base which faces an opening to the substantially U-shaped housing; wherein the opening to the substantially U-shaped housing faces out from one of the side of the base and the side rim of the top.