Poke-in termination for magnet wire
The 1217357-1 is the Size 4 member of TE's Mag-Mate poke-in terminal line, designed for 19.5-21 AWG magnet wire with an IDC termination that pierces the insulation in one operation. Style 500 denotes the specific contact geometry for this wire range; the terminal ships in Tape & Reel (TR) and Cut Tape (CT) packaging for automated or hand placement.
Size 4 vs Size 2 in the Mag-Mate series
Within the Mag-Mate family the 1217357-1 (Size 4) accepts 19.5-21 AWG wire, while the 1394476-1 (Size 2) covers 18-20 AWG — the wire gauge range is the selection axis; the poke-in IDC termination method is shared across the series.