Pistons ensure that the pressure is evenly spread across the fluid surface to provide consistent dispensing. Wiper seal pistons prevent dripping and eliminate material waste by wiping the syringe barrel wall clean as fluid is dispensed. Maximum operating pressure is 100psi (6.9bar).

"Easy Flow" Pistons (blue) are recommended for most general applications and they ensure no material residue is left on the syringe barrel walls while dispensing. 
Wiper Pistons (white) are a tighter fit for use with very low viscosity fluid or with mechanical devices such as the TS700 manual syringe gun to prevent leakage past the double wiping edges. 

Straight Wall Pistons (red) are recommended for reduced stringing and "bouncing" with high viscosity products.