These collars were made for civilian use during the period of clothes rationing in Great Britain.
Clothes rationing was introduced to ensure that everyone had an equal opportunity to buy clothing.
Much of the available resources were used to make uniforms and blankets for the armed forces, leading to shortages of clothes.
Civilian clothing had to conform to government economy standards.
The CC41 mark stamped on this collar shows that it met these requirements.
Like all civilian clothing during rationing, people buying collars needed to pay for them in the normal way, but each purchase had to be accompanied by the appropriate number of clothing coupons.