It is advertised as an excellent test device, durable and multifunctional. I find the test set less than adequate. The speakerphone is unstable, as is redialing the saved and last number. I've been in the phone business for over 30 years and have used several test kits (Harris, Fluke, Dracon). I was particularly disappointed with the Eclipse. I need time to buy a product and then I have to return it. It works well. Enough for testing beeps and ID numbers, but when you need to check a lot of numbers or are in contact with Clec, speakerphone is essential and Eclipse just can't handle it. I recommend you spend a few more dollars and buy a good one.