Outside surface with fabric insert reinforcement. Oil Seal without metal reinforcement. Split Seals also available. These are frequently installed back to back with a lock-in plate. They are available in NBR and FPM.
Similar to type WR35, but additional grooves on the back side for optimal grease supply to the sealing lips when back-to-back mounted.
Similar to type WR36, with grooves on the whole contour.