The Square Rabbit QA Phantom consists of five square 30 x 30cm slabs 2 - 5cm thick slabs, 2 - 4cm thick slabs and 1 - 2cm thick slab. The slabs are constructed of ultra-high molecular weight polyethylene with a density of 0.928 - 0.941 g/cc (depending on the source of reference). The outer slabs have radius cut edges.
The slabs can be drilled to support an ion chamber. Two film fiducials in the 2cm slab allow for easy marking of film for absolute registration.