I got the first alert hardwired and so far so good. I read for smoke detectors you technically want two types of smoke detection and they have both.

https://www.amazon.com/dp/B07B4CG1PG/ref=cm_sw_r_cp_apa_i_f9TrFbCZ1FRQN

If you want a CO detector, I'd say buy that separately because CO sinks while smoke rises.