Super Glue in a 6x3 magnet and use like the original. The 2.5 torque rating is from HarcosDesign 2.5nm rotor remix.
The author remixed this model.
Modified the cap to add 2.5 to the top for the torque rating from the 2.5 rotor in HarcosDesign remix: https://www.printables.com/model/584224-nozzle-torque-wrench-25nm/