Patent ID: 7040603

Claim:
A square leveler block formed in a single and unitary molding step of a polymer resin with main side walls defining an outer square shape, the main side walls sealingly capped by a base plate and four square raised parts comprising: (a) an underside cavity substantially immediately beneath each of the raised parts, the underside cavity comprising four flanged posts, where each of the four flanged posts are adapted to interlock with a key recess defined in a raised part of another identical leveler block when that raised part of the other leveler block is located within the underside cavity; (b) the raised parts have raised part side walls sealingly capped with a top plate and the raised part side walls are aligned with their sides parallel with the main side walls; and (c) each raised part defines four key recesses, one key recess extending in from each of the four raised part sidewalls.