Grandstream DP722 DECT, 10 SIP, 10 Lines, Silver//Supports a range of up to 350 meters outdoors and 50 meters indoors when used with the DP752 (300 meters outdoors when used with DP750)1.8 inch (128x160) color LCD with 2 programmable soft keysOffers 20 hours talk time and 250 hours standby timeSupports up to 10 SIP accounts and 10 lines per handset as well as 3-way conferencingPush-to-talk via a configurable buttonSeamless 1-touch door control with Grandstream’s GDS series of Facility Access devicesHD audio on the speakerphone, handset, and headset jackSoftware and firmware updates over-the-airhttps://www.grandstream.com/products/ip-voice-telephony/dect-cordless/product/dp722