This style limit stop was used on some older Hunter Douglas Silhouette sheer shades made before May 2008. It is no longer manufactured and is not available for purchase. 

We carry a compatible replacement limit stop that works in its place.

Limit stops prevent the shade fabric from over-rolling on the metal tube at the top of the shade when the shade is raised. 

This limit works on shades with the "Standard" end caps that measure 3" at the widest point.

This part works on a shade with a tube that looks like this: 

White plastic.

Sold individually.

Hunter Douglas part # 4150057885.