Reolink camera models that support two-way audio are:
Applies to: E1, E Series E320, E1 pro, E1 Zoom, E Series E340, E1 Outdoor Series, Reolink Lumus, RLC-511WA, RLC-523WA, RLC-840WA, W337, RLC-843WA, W437, RLC-540A, P327, RLC-811A, P430, RLC-812A, RLC-823 Series, RLC-824A, RLC-81MA, P330M, RLC-81PA, P330P, RLC-830A, P830, RLC-833A, P434, RLC-843A, P437, RLC-840A, P337, RLC-1240A, P347, RLC-1212A, P341, RLC-1224A, P345, B1200, P341C, D1200, P345C, FE-P, Fisheye Series P520, FE-W, Fisheye Series W520, CX410, ColorX Series P320X, CX410W, ColorX Series W320X, CX810, ColorX Series P330X, CX820, ColorX Series P335X, Reolink Duo series, Reolink TrackMix series, Reolink Video Doorbell series and all Reolink battery-powered cameras.
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.