Nordson EFD Optimum syringe barrels feature ZeroDraft walls with consistent internal diameters that maintain an airtight seal with pistons to ensure accurate, consistent fluid deposits, eliminating the need to deal with messy blow-by, pressure variation, or contamination. The supplied pistons are inserted into the syringe barrel after it has been loaded with fluid to ensure uniform dispensing force and prevent dripping and oozing between shots.