are identical as illustrated in fig1 a complete opening includes angular cutouts 2 c 12 a and 2 c 12 b repeated along the periphery of opening 2 ca when plates 10 and 20 are joined as illustrated in fig1 angular cutouts 2 c 12 a and 2 c 12 b may have different angular patterns depending on the desired adjustability of a connector inserted within opening 2 ca in the preferred embodiment the angled cutouts are 45 degrees with respect to each other referring to fig5 7 a connector 5 is disclosed for use in the present invention it is understood that any type or shape of connector 5 may be utilized with the present invention provided it includes a channel or recess for attachment to the plate as herein described the connector 5 is designed to include a channel 5 a cut within its body as illustrated in fig6 and 7 channel 5 a is of sufficient width to slideably engage and snugly fit angled cutouts 2 c 12 a and 2 c 12 b repeated along the periphery of opening 2 c into channel 5 a up to a point where connector 5 bottom surface 5 a 1 contacts the periphery of opening 2 c and depending on the angular orientation of.