The SPEED Magazine Catch Button eliminates the need to depress the button into the receiver in order to remove the magazine catch from the other side of the receiver. Without the SPEED Magazine Catch Button, you will always risk scratching up the receiver every time you need to remove the magazine catch. The SPEED Magazine Catch Button installs and removes in seconds without depressing the button. A special rotating inner ring within the button quickly threads the button onto the magazine catch with the aid of a special SPEED tool, which is included. This is a great upgrade for those who spend a lot of time tuning and fear marking up the receiver every time they have to remove the magazine catch. Please note that these ONLY work on M16 / M4 style catches that have a threaded release button and shaft. They are NOT replacements for the Marui style catch with a small screw holding the button in place.