Abstract: A slab bolster element includes a frame member having a male connector at a first end and a female connector at an opposite second end. The male connector includes a substantially solid insertion body with a surface having a transverse locking groove. The female connector includes a receptacle body configured to receive the insertion body of a complementary male connector, and a resiliently flexible locking tab positioned and configured to resiliently deflect to allow the insertion of the insertion body of another slab bolster element into the receptacle body, and to resiliently engage with the transverse locking groove of the insertion body when the insertion body is received within the receptacle body. The resiliently flexible locking tabs can be oriented any direction to mate with similarly shaped male connectors, and material can be strategically removed from standoffs and connectors to minimize the use of materials.

Abstract: A mask assembly includes a mask body configured to cover a wearer's nose and mouth. The mask body has a breathing area with breathing openings and a straw port. A replaceable filter medium is configured to cover the breathing openings on the interior of the mask body when installed thereon in a removable filter medium retainer element. A removable face plate overlies, and is spaced from, the breathing area on the exterior of the mask, so as to allow air to flow through the breathing openings and around the sides of the face plate, while blocking particulate matter from passage to or from the nose or mouth of the wearer. The face plate, the filter medium retainer element, and the filter medium may have openings that are alignable with the straw port.

Abstract: A slab bolster element includes a frame member having a male connector at a first end and a female connector at an opposite second end. The male connector includes a substantially solid insertion body with a surface having a transverse locking groove. The female connector includes a receptacle body configured to receive the insertion body of a complementary male connector, and a resiliently flexible locking tab positioned and configured to resiliently deflect to allow the insertion of the insertion body of another slab bolster element into the receptacle body, and to resiliently engage with the transverse locking groove of the insertion body when the insertion body is received within the receptacle body. The resiliently flexible locking tabs can be oriented any direction to mate with similarly shaped male connectors, and material can be strategically removed from standoffs and connectors to minimize the use of materials.

Abstract: A slab bolster element includes a frame member having a male connector at a first end and a female connector at an opposite second end. The male connector includes a substantially solid insertion body with a surface having a transverse locking groove. The female connector includes a receptacle body configured to receive the insertion body of a complementary male connector, and a resiliently flexible locking tab positioned and configured to resiliently deflect to allow the insertion of the insertion body of another slab bolster element into the receptacle body, and to resiliently engage with the transverse locking groove of the insertion body when the insertion body is received within the receptacle body.