The C8516 is MICRO JST, PH, PLUG & SOCKET 1.25mm 4 pin
The C8515 is Mini Micro JST 2.0 PH 4 Pin
The light socket on the C8515 is Micro JST ZH 1.5mm 4 Pin
The C8515 is Mini Micro JST 2.0 PH 4 Pin
The light socket on the C8515 is Micro JST ZH 1.5mm 4 Pin