... Video Door Phone,2.4G lauch frequency,Power just 20dbm,remote control around 150-180M. Wireless Video Door Phone:>If you ... frequency, the power is no more than 20dbm, non-obstacle remote control is around 150-180m; >With micro-dealing technology; auto ... ;>Clear night-viewing, 24 hour monitoring, calling , speaking and unlocking remote controlling, etc; >One indoor video phone can control 1 pcs outdoor ...