<p>The invention provides an assembly (20) for release of an element (8) such as a hatch. The assembly (20) includes first means such as a peg (28) moveable between a first position in which the first means (28) restricts full release of the element (8) and a second position in which the first means (28) does not restrict full release of the element (8), and second means, such as shape memory alloy wire (32) which is adapted to contract when activated to move the first means (28) from the second position to the first position. Optionally, the assembly (20) includes third means, such as shape memory alloy wire (34) which is adapted to contract when activated to move the first means (28) from the first position to the second position. The assembly (20) is useful for testing oxygen release apparatus in aircraft.</p>
