Brand New 4 Swivel Galvanized Square 5 1/2"x 5 1/2" Quality Base Plate With 2" Position Holes Compatible with any 1.69" or 1.625" Frame Tubing This Auction is for Set of 4 Quality High Strengh Steel Base Plates It is impossible for a stable structure to be built upon a foundation that does not start out square and level. OSHA has standards that apply specifically to the steps that must be taken to assure a stable scaffold base. Note: Except where indicated, these requirements also apply to manually propelled, pump jack, ladder jack, tube and coupler, and pole scaffolds, as well as the specialty scaffolds described in the Supported Scaffolds module