A blister piercing element for puncturing the lid of a blister containing a dose of medicament for inhalation by a user, comprising a body having a surface and an opening in the surface for the passage of air, or for the passage of medicament entrained in air, through the body, wherein the body includes a pair of spaced cutting teeth (8, 9) upstanding from the surface in spaced side-by-side relation, the teeth (8, 9) being symmetrical about a plane extending between the teeth (8, 9), which is perpendicular to the surface, each cutting tooth (8, 9) projecting in cantilevered form over said opening, each tooth (8, 9) comprising an upright portion extending from the surface adjacent to, or from, a periphery of the opening and a cantilevered portion that extends from an upper end of the upright portion and projects out over said opening, each tooth (8, 9) having a distal cutting edge (13, 14) at a free end remote from said surface, each tooth (8, 9) further comprising an apex that lies on the distal cutting edge (13, 14) and which is configured for initially puncturing a blister lid, said distal cutting edge (13, 14) extending away from the apex of each tooth (8, 9) in two different directions and at an angle towards the surface, wherein a first part of the distal cutting edge of each tooth (8, 9) extends from the apex in a direction toward the apex of the other tooth (8, 9) and a second part of the distal cutting edge of each tooth (8, 9) extends from the apex in a direction away from the other tooth (8, 9), a secondary cutting edge extending from the apex of each tooth (8, 9) along the cantilevered portion towards the upright portion, the first part of the distal cutting edge of each tooth (8, 9) being configured to initiate a slit in the blister lid initially punctured by the apex of each tooth (8, 9) and the secondary cutting edge configured to cut a further slit in a direction extending away from the apex along the cantilevered portion towards the edge of the blister lid from which the tooth (8, 9) upstands when pressure is applied to the blister lid by the teeth (8, 9), the teeth (8, 9) being spaced from each other so that the slits cut by the first part of the distal cutting edge of each tooth (8, 9) propagate in a direction toward each other between the teeth (8, 9) as the teeth (8, 9) continue to penetrate the blister lid, so that a single continuous slit is created by the secondary cutting edges and the first part of the distal cutting edges, thereby forming a flap which is folded into the blister by the teeth (8, 9) as the teeth (8, 9) penetrate further through the blister lid characterised in that the opening has first and second opposite edges (10a, 10b) and the teeth (8, 9) upstand from the surface adjacent to the first edge and project in cantilevered form in a direction towards the second edge to an extent that the distal cutting edge (13, 14) is closer to the second edge than to the first edge, wherein the first part of the distal cutting edge of each tooth (8, 9) extends from the apex towards said surface at an angle which is shallower than the angle at which the second part of the distal cutting edge of each tooth (8, 9) extends from the apex towards said surface.