Neewer NW420-S 2.4GHz HSS 1/8000s TTL Wireless Master Slave Flash Speedlite Compatible with Sony A9 A7RIV/III A7III… Price: $89.99 (as of 24/09/2022 12:44 PST- Details) & FREE Shipping.

High Guide No.36 (ISO 100), Full TTL Functions, Support HSS(Max.1/8000s), Front & Rear Curtain Sync
Flash Mode: TTL, M, Multi, FEC, Master, Slave, S1, S2
22 steps of power output (1/1-1/128), Approx.0.1-2.2s Recycle Time, 210 Full Power Flashes, 24-105mm auto/manual zooming