Really, this is just an ordinary lever, but mounted the other direction. I have to admit though, if you picture a pressure bar overlying a sac, pressing from the barrel end with progress towards the section and nib just might allow for better air expulsion and therefore better filling of the sac. Functionally, however, there probably is no difference. Eisenstadt pens are high quality and the right angle logo is seen on the lever and nib. Hard rubber is typical but metal pens are occasionally seen.