A big development in life jackets saw the Mk9 come into existence for the purpose of being blast-proof for higher speed ejections.
It was a complete re-design over the predecessors, who all had shared similarities in waitcoat, and stole container design.
The Mk9 brought about a completely new stole container, with new stole deployment system, and was constructed from new materials. It was also the end of bright yellow life preservers, bringing in green and grey colours.
Source: Flight International Archive, part of an article on the 1967 USIAS Paris Airshow at Le Bourget.
Quote:
Frankenstein Group Ltd. Victoria Rubber Works, Newton Heath, Manchester 10
Mk9B blastproof aircrew jacket tested to 650kt at ground level.
The Mk9 life preserver is shown as item 11 in this AEA poster.