The BF 250 is supplied with a special collet, type SPV 12-3/8, to create a quick connect and disconnect system for an STR vertical support rod. This can simply be plugged into the collet and tightened by hand with a half turn of the milled cap nut.
The chuck SPV 12-3/8 is also available separately for the purpose of updating older equipment. It can be screwed on with a open-ended wrench.