Reolink camera models that support two-way audio are:
E1, E1 pro, E1 Zoom, E1 outdoor, E1 Outdoor PoE, E1 Outdoor Pro, Reolink Lumus, RLC-511WA, RLC-523WA, RLC-811A, RLC-812A, RLC-823A, RLC-823A 16X, RLC-824A, RLC-81MA, RLC-81PA, RLC-830A, RLC-833A, RLC-1212A, RLC-1224A, B1200, D1200, FE-P, FE-W, CX410, Reolink Duo series, Reolink TrackMix series, Reolink Video Doorbell PoE, Reolink Video Doorbell WiFi and all Reolink battery-powered cameras.
Note: Some camera models are discontinued right now, for models on sale, you can order here: https://store.reolink.com/
If you want to use the two-way audio of your camera to talk with others, the following are the steps for teaching you how to enable the two-way audio.
Note: Ensure the microphone/speaker could work on your Phone/PC before using the two-way audio.