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 Does the 2000 series have a request to exit switch? Precision 5000 Series Illustrated Parts Breakout Catalog 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