This hold down bracket is used on Shangrila sheer shades that are manufactured by Comfortex, 3 Day Blinds, and Blinds Galore. It has an integrated pin that fits into a hole in the bottom rail of the shade.

Clear plastic. Uses size #6 mounting screws that are sold separately.

The diameter of the pin is 3/32". 

Sold individually.

Comfortex part # CS5042.