US Patent 7186915 Mud box and adapters

A square electrical box molded in one-piece of plastic material has three connectors extending outwardly from each box sidewall for receiving different sizes of electrical nonmetallic tubing. The box internal corners are occupied by bosses that extend the full height of the corners and have fastener receiving holes therein. Attachment ears extend outwardly from the box, and an adapter attachable to a front surface of the box has attachment ears aligned with the box ears. Fastener receiving holes through the ears are configured to receive fasteners that are inwardly inclined toward the box central longitudinal axis.