The Yealink EXP40 Expansion Module is for all compatible SIP-T4x Yealink phones (check product compatibility on phone page).
Yealink EXP40 IP Phone Expansion Module Key Features
- 160x320 graphic LCD with 16-level grayscales
- LCD Backlight
- 20 physical keys each with a dual-colour LED
- Wall mountable
- Supports up to 6 modules daisy-chain