Base plate 20x20AThe base plate 20x20A is an aluminum 20'' x 20'' square baseplate that fits the 12'' square and I beam truss, the 8. 5'' square and triangle truss and the 4'' square truss. This plate offers a good balance between weight and size for the 4'' and 8. 5'' truss sizes. For the 12'' it is a good step up from the standard 12'' base allowing for more room to bolt the truss down or area on which to place sandbags. The handle cut out is convenient for moving