YEALINK T53 Well suited for common workspace 3.7″ (360 x 160) adjustable LCD screen21 memory keys (3 page of 7 keys)Up to 12 VoIP accounts3-ways conferencingUSB 2.0 portHeadset portEXP50 : expansion module supportedNo power supply assignmentDatasheets↪ Yealink T53W Datasheet (EN)↪ Yealink T53W Datasheet (FR)↪ Yealink T53W Datasheet (DE) library_booksUser guides↪ Yealink T53 & T54 User Guide (EN)↪ Yealink T53 & T54 User Guide (FR) ↪ Yealink T53 & T54 User Guide (DE)