Can' t help ya . . . I have used cats whiskers since the 1960' s. Trimmed to about 1-1/2" long they work great fot me and it is the bottom line that counts . . . my pocket book rates next.

All that said I am a STRONG believer in Sims Products . . . just not the String Leaches . . . although they are great . . . they just don' t last long enough for my budget.