1. Make worldwide calls from your computer. 2. High quality termination for your IP PBX (Asterisk, FreeSWITCH, etc.). 3. Make calls through local access numbers. Now you can make long distance calls from your home, mobile, office phones at low rates. 4. Callback service. World travelers can use our callback service to make inexpensive calls from anywhere in the world. 5. Web-based "Call Now" system. Calls can be activated from your computer by telling Diamondcard.us the number to call and the number you are calling from.