This invention is a reverse buckling rupture disc (12) having a mounting flange (20) and a pressure rupturable member (24) where the rupturable member has a one piece rupture disc with a pair of dome shaped members (22,24) projecting outwardly from the flange and where both domes are lying in the same axial orientation. The first dome shaped member (22) comprises a lower, generally arcuately shaped, wall extending in the axial direction in an arcuately and inwardly oriented configuration. The second upper dome shaped member (24) is comprised by a second arcuately shaped and inwardly extending wall which has a diameter less than that of the first dome shaped member and where the second arcuately shaped wall extends from the first arcuately shaped wall. The rupture disc assembly has a support ring adapted to support the rupture by a central aperture and means adapted to initiate a tear in said rupture disc.