Wylex NM21FLA Conversion Kit 21 Module\r\n- Consumer Unit Flush Lid Assembly, 21 Module.- All metal flush lid kit.- Flush kit for surface mounting consumer unit.- Suitable for a 21 module NM consumer unit.- Size: 300x471mm.\r\nThe Wylex NM21FLA is a 21 module flush mounting kit, which can be used to assist with the installation of metal NM consumer units. he NM21FLA Flush Mounting Assemby is designed with the following Consumer Units in mind - NM1906, NMRS1906, NMR15SSLMHI or any other Wylex NM Consumer Unit Measuring 438mm (17.2") in Width.