The Hoop Shields were designed to protect the various size embroidery hoops from adhesive overspray when embroidering on top of the hoop.  

No more sticky hoops to clean of thread glue and lint, and because you are not putting fabric on the shield you seldom need to clean hoop shield.  

Medium 8" x 5 1/2" fits Embroidery Hoops for HUS 5 x7
Large fits the 240 x 150 hoop

For a cleaner embroidery experience. Hoop Shields were made to fit the embroidery hoops for the 
Baby Loc
Bernina 
Brother
Janome
Pfaff
Elna
Huskvarna
Singer 
and others