This INTRAFUSE® SKS Extended Mag Catch allows you to easily get a hold of the mag catch for quick and easy removal of your mag. Works with standard SKS magazines only. Will not work with SKS rifles that accept AK-47 magazines, such as the Model M or D. Some Yugoslavian SKS rifles will require minor modification to achieve perfect function. To install; press in the pin behind trigger to release trigger group at the front of the trigger group there is a pin that holds the mag catch in punch pin out 95% of the way once the pin is clear replace with new tapco catch due to the difference in sks models you may have to make the channels in the mag catch slightly deeper.