NEMA FB 2.20-2014 Selection and Installation Guidelines Fittings for Use with Flexible Electrical Conduit and Cable was amended to address possible incompatibility between cable dimensions and legacy MC cable fitting designs. Specifically, guidelines included within this NEMA-published standard provide installers and inspectors industry perspective of best practices in selecting and installing fittings for AC and MC cables, NM cable, FMC, LFMC, and LFNC that NEMA members manufacture.