Cavens Timber:  This is considered a beaver call/gland lure.  It is made with the fullest castors available and are ground. According to Caven, he adds the loudest, and effective calling agent he knows and all of this put into a waterproof base creating Timber!, a beaver lure supreme. 

Dobbins Backbreaker:  This is a heavy castor-based beaver lure.  It's great for all times of the year, but works best during the late fall through spring.  A staple for many pros.

Sweetwater Flattail:   This is a closely guarded secret from the state of Wyoming since early in the 20th century.  No expense has been spared in this formula.