AJP/Braktec part number: 129.00.002C
Braktec/AJP Rear Brake Master Cylinder - DOT 4 - Black
GasGas Pro
9.5mm piston kit
Also fits the older TXT bikes, will fit as a replacement to R350100, older m/c used an 11mm piston, so the feel will be different replacing with this.
Also fits: Scorpa Easy 250/290