Original german dyne hilldare pen, electroshock pen, surface tension test pen 28-72 mn/m

Dain pen, also known as the surface tension test pen, the electroshock treatment pen, and the plastic film surface tension test pen. It is a test tool for the electro-stunting (dain) of the thin membrane surface, which is used to determine the effects of the membrane subject to electroshock treatment。
Volschleg group, germany。