Yealink YEA-EXP39 IP Phone Expansion Module:

• Yealink LCD expansion module
• 160x320 graphic LCD with 16-level gray scales
• 20 Physical keys each with a dual-color LED
• 20 Additional keys through page switch
• YEA-EXP39 supports up to 6 modules daisy-chain
• Different icons for each function shown on the LCD
• Dial-color LED for status information
• Supports busy lamp field, bridge line appearance 
• YEA-EXP39 is programmable for speed dialing, call pickup, intercom, hold, transfer, voicemail, forward, DND
• Applies to Yealink IP phone SIP-T28P and SIP-T26P and SIP-T38G
• Expansion module is powered by the host phone
• 2xRJ12 (6P6C) ports for data in and out
• Weight: 290g