ISDN TELEPHONE SET - CUSTOM OR NATIONAL?

• A 970 ISDN Telephone is always a National ISDN telephone set. A 970 telephone has twelve (12) buttons:  three  (3) rows with four (4) buttons on each row. 
• The 1050 ISDN Telephone is an eighteen- button set:  three (3) rows with six (6) buttons on each row. It can be either Custom or National.
• To determine if the 1050 ISDN Telephone is Custom or National - turn the set over. If there is a  white tag that reads SRS-1050 NI, it is a National set.  If the white tag reads SRS-1050 ESS, it is a Custom set.
• Another way to determine if the 1050 ISDN Telephone is Custom or National is by the set color: Beige/White = Custom; Black = National.