The UIC | Wiper Roller OD 12 / 9 x 16.5 is an OEM PTFE wiper roller (OD 12 / 9 x 16) for the UIC KDL5 molecular distillation system. The wiper rollers ride on the inner glass evaporator wall, spreading feed material as a uniform thin film for efficient molecular evaporation. PTFE construction ensures chemical inertness and low friction without scratching the glass evaporator surface. Replace as a complete set during preventative maintenance to maintain uniform film distribution.