Seek Philips CORD282 landline manual ringtone how to adjust the

Philips CORD282 landline, there is no ringtone selection, only adjust the volume. Hands-free volume and ringer size adjustment:

Press the volume key in hands-free dialing and call state can be 4-speed cycle to adjust the volume of the speakerphone; in the hang-up state, press the volume key can be 4-speed cycle to adjust the volume of the incoming ringer sound

Section of the incoming ringer sound. (The display "--------" means maximum, "---" means minimum).