Mag-Mate IDC terminal for 21.5-23 AWG
The 1217358-1 is a Size 4, Style 500 IDC poke-in terminal in TE's Mag-Mate series, accepting 21.5-23 AWG magnetic wire.
Size 4 vs Size 2 in the Mag-Mate line
The 1217358-1 (Size 4) handles 21.5-23 AWG wire, while the 1394476-1 (Size 2) takes 18-20 AWG — the size designation tracks the wire gauge range, not the terminal body dimensions.