What is the dogging key size and part number? July 20, 2022 13:45 Updated Answer 7/32 standard hex. DK220, the part number is 7126075 Applies To Apex 2000 (3R) Additional Information Related articles Precision 2000 Series Surface Vertical Rod Exit Device Precision 300 Series Mortise Cross Bar Precision 2000 Series Rim Exit Devices My Arm-A-Dor is beeping at me twice every few seconds. How do I program my Keypad EZ?