Abstract: A connector comprising a container-like fastener holder (4) of finite depth with a front (6) and a rear plate and side walls (8) wherein the rear wall and substantially the whole depth of the holder can be cast into a concrete structure to form a space within the concrete structure, fastening means (12) which can assume a range of positions within the holder (4) and a move able connection part (16) or device which can be fastened to the front plate (6) by the fastening means (12).