This device is a kind of powerful multi-function call blocker which can block numbers added to blacklist, with the Pro call Blocker, your world finally get quiet. * Note: 1. This product requires Caller ID service from your network provider.  All calls without Caller ID will be rejected directly.              2. The new and old model differ in LOGO pattern, and they are in random delivery.  Large Capacity: Block nuisance or unwanted calls up to 1000-1500 groups. Add or Remove Blocked Number: Manually enter or remove numbers to/from the Blocking list. Block Area Code: Blocks the Area Code or the first few digits of a incoming calling number. (Hint: Limited to 10 Groups) Block NO Caller ID Calls: This will block all calls without caller ID. Ring Setting: You can choose 1-Ring or 0-Ring for blocked calls. Unblock Number: To delete a blocked numbers. Hit "BLOCK" button first, then hit Left or Right arrow to view the blacklist.  Select the number and press DELETE twice quickly. The DONE should show indicating the removal of the number from the blocked calls. Specifications: Type: Caller ID Blocker Model: CT-CID803 PLUS Material: ABS Color: Black LCD Display: Backlight Keys: SET, OUT, BLACKLIST, REMOVE, UP / DOWN Product size: Approx.10 * 8.6 * 4.4cm / 3.9 * 3.2 * 1.7in  Product weight: Approx.87g / 3.1oz Package size: Approx.10.2 * 9.5 * 5cm / 4 * 3.7 * 2in Package weight: Approx.124g / 4.4oz Package List: 1 * Caller ID Blocker 1 * Network Cable 1 * User Manual (English)