This is BAB2SF SEAL 42*72*6.5 VITON High Pressure Shaft Oil Seal for hydraulic pump , such as PARKERMOTOR F1-025-M , those pumps usually are usred in roader roller, land scraper, shovel loader, self-discharging car, mixer truck and excavators etc. 
 
Medium pressure seals, such as the BABSL, can be used in many applications including pumps and motors in hydro-units, mechanical power transmission gearboxes, and 2-stroke engines. However in conventional seal designs, as pressure increases the seal life dramatically decreases due to atypical seal wear that is caused by pressure distortion of the seal lip geometry and increased friction at the contact point. The BABSL minimizes those problems over a wide range of operating conditions.