1940s White Silky Lingerie Guard - With Instructions !

NO MORE UNSIGHTLY STRAPS
NO MORE SLIPPING SHOULDER STRAPS
So, nothing ever to worry about ever again..
AND, there are instructions on the back
"pin to inside of dress at shoulder seam
simply fasten round your straps"
The (folded) length of the ribbon is 3.5cm and 1cm wide.
There is a little gold safety pin at one end and a white press-stud at the other.