These Godox flash triggers seems really promising. I have used Allacax units for a couple of years but the transmitter uses a V23 battery and their availability is poor. Cells II is quite big but these use AA batteries and that is really nice as flashes use same batteries so no more separate spare batteries. Range is very good too. Transceiver design is nice too, if transmitter runs out of juice separate transmitters and receivers are useless. Price isn't very high, 4 units for 90 Euro (RF-602 transmitter and 3 receivers is about 40 Euro but the transmitter uses a uncommon battery and construction isn't great [neither from Yongnuo or Wansen]). It would be really attractive solution if Godox will make a Sony version of V860 but really useful with one V850 and 2 cheap manual flashes too.