A prosthetic liner for receiving a residual limb has a body with an open
proximal end and a closed distal end. The liner includes a seal having an
annular sealing lip positioned about the body axis on the body distal
end. The sealing lip includes a root that is secured to the body distal
end, and a sealing edge that extends from the root so as to form an
opening and is biased away from the body distal end.