i've done a couple, and they are a little strange, follow the book to the letter. you have to go into program mode at the console after you've added it in the switch. they work if your stations are in a 150 (memory) range.. the keys start a x and run for the next 150 stations, you can use a shift button to increase the range but that renders it even less user friendly. i would do my best to talk a company out of one if they have over a hundred stations
john poole
bellsouth business
columbia,sc