Description Literature Description Freudenberg Sealing Technologies (formerly Tobul) seal set used with 6.7A20 Piston Accumulator Series, FKM (Viton). Seal sets are used to seal the gap between different parts of the hydraulic cylinder used as direct replacements for seals in order to keep equipment running properly. State of California Proposition 65 WARNINGCancer and Reproductive Harm - www.P65Warnings.ca.gov. Literature & Docs Accessories