A seal and a mask using a seal that includes a first end portion adapted to be coupled to a seal support, a second end portion adapted for sealing engagement with a face of a user, and a sidewall extending between the first end portion and the second end portion. The first end portion, second end portion, sidewall, or any combination thereof is formed from an elastomeric material having an elongation of at least 1000%. The seal preferably formed from a unitary piece of elastomeric material.