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 8300/F8300 Rim Exit Devices Templates & Installation Instructions 9100/F9100 Wide Stile Concealed Vertical Rod Exit Devices Commercial Hardware Mortise Cylinder Configurations for BEST 45 H and 45HW Apex 2000 Series Metal Door Concealed Vertical Rod Devices Apex 2000 Series Rim Exit Devices