A connector includes a receiver member having a hollow rectangular tube to be cast with a structure. An attachment member has a post extending with a pin extending radially through the post at a distal end. The pin is shorter than the longer rectangular dimension and longer than the shorter rectangular dimension. When the attachment member is positioned adjacent the receiver member and oriented with a longitudinal axis of the pin parallel to the longer rectangular dimension, the post can be inserted into the hollow tube and rotated to a position where the pin abuts a distal end of the hollow tube to lock the attachment member to the receiver member.