I am aware of the G2 from G. I have not been able to order a SPA525G2 from any of my vendors for the last couple months at least and when you visit some of their websites it states that they are Discontinued while some state that they are on Backorder, but dont have an ETA for delivery.
If you do a quick google search you will see several pop up.
Configure Multicast Paging on the Cisco IP Phone 7800 Series or 8800 Series Multiplatform Phone
The Cisco IP Phone 7800 and 8800 Series Multiplatform Phones provide voice communication over an Internet Protocol (IP) network...
Add Call Park on a Cisco 7800 or 8800 Series Multiplatform Phone Key Expansion Module
Call park allows the user of the phone to put an incoming call on hold so that the call can be retrieved on another phone. A call is park...