The first Zortrax hot end (V1), in 2014, was all-metal. It didn't work with Z-Glass, so they released the V2 in 2015 (I think). The V2 had the same construction but included a plastic (PTFE?) insert at the top of the heat break. The V2 worked better with Z-Glass but still won't print most PLA, flexible, etc., which is why ZT-HE was developed. Its construction is significantly different from the Zortrax V2, but it is certainly compatible with all M200 heaters, thermocouples, and thermocouple amplifier PCBs.