A seal assembly and an apparatus including the same are provided. The seal assembly may include a seal member with axially opposing sides and one or two back-up rings for substantially supporting at least one side of the seal member. The seal member may be made of elastomer and have an axially extending base with one or two flange portions and a protrusion extending perpendicularly from the base. The back-up ring may be made of a plastic material and a portion of the back-up ring may abut a radially outer surface of the flange portion of the seal member.