Straight Squeeze Type Malleable Iron BX-Flex Connector for Metallic Conduit, AC and MC Cable (250, 1/2") - - Amazon.com
4 in. Square Box, Welded, 2-1/8 in. Deep with AC/MC/Flex Clamps, Three 1/2 in. KO's and One TKO, Box-LOC, MS Bracket, Flush: Amazon.com: Tools & Home Improvement