Hi all. I have a question: I think I understand what a clutchless piston filler is. The piston is operated by a threaded helix. You turn it to push the piston up or down, or keep turning the same helix beyond its stop point to disassemble the piston/pen. What is a clutch on a piston filler? I haven't been able to find information. I am asking also because I have a piston filler that I intend to disassemble and it does something that makes me think it might be a clutch type, but I would like to know what that is first. Best regards