DESC: Compatible with KX-TS4200B and KX-TS4300B telephones for use as additional extensions Corded Phone System Up to 4-Line OperationExpandable Up To 16 Stations Selectable 3-Way Conferencing Speakerphone at base Backlit multifunction LCD screen 24-Digit Per Station Dialer Storage Capacity - perfect for international phone numbers 32 One-Touch Memory Buttons6 Number Redial Adjustable Handset Volume Control 8-Step Speakerphone Volume Control 4-Step Ringer Volume Control plus Ringer On / Off Convenient Line Selection - Group / Prime / Auto Intercom / Voice Paging / Call transferHold / Mute / Redial / Flash Selectable Do Not Disturb mode Real Time Clock AM / PM Format Wall Mountable or May be used on Desk or Table 2 Desktop Angle Choices Power Outage Operation (Requires Battery) 2.5mm Headset Jack foradding an Optional phone headset Bilingual Menu Support (English / Spanish) Can work during Power Outage (requiresbattery)