Five C02 gas cylinders, 1962-63.

Five C02 gas cylinders which were used on powered upper limb protheses. The bronze anodized, BOC cylinder (centre) was the original type and was first used in November 1962. This was replaced by the steel grey Chesterfield cylinder in 1963 (second from the right). It was considered dangerous if incorrectly handled and was soon withdrawn. This type was then replaced by a Walter Kidde cylinder (left).