Why would you want a reed with the patented "Sound Plate" feature• Your chance for success depends on how accurately you reproduce the elk language.• The Sound Plate automatically positions the call at the right angle, which allows you to reproduce both cow and bull language with one call (no more switching calls).• The Sound Plate also supports the reeds so they won't ever stretch like conventional reeds - they will last an entire season!- Sound Plate Hyper Plate Double Elk Mouth Call -The Sound Plate automatically positions the call at precisely the right angle, making calling easier. The Hyper Plate Double has 2 reeds with a "Y" cut in the second reed, which is perfect for hyper estrus cow talk and heard bull bugles.- Sound Plate Imperial Plate Double Elk Mouth Call -The "Sound Plate" automatically positions the call in your mouth at the right place and angle, making calling elk easier. The 30 Degree angle of the Sound Plate, the double-reed design and "V" cut in the bottom reed make the Imperial Plate Double perfect for reproducing cow and herd bull sounds. The "V" cut also adds to the raspy sounds of the herd bull's growl, bugle, and chuckle.- Sound Plate Ivory Plate Single Elk Mouth Call -The Sound Plate automatically positions the call at precisely the right angle, which makes calling elk easier. The Ivory Plate Single has a Sound Plate set at 30 Degree, which is perfect for cow, calf talk and satellite bull bugles.- Sound Plate Sentry Plate Single Elk Mouth Call -The "Sound Plate" automatically positions the call in your mouth at the right place and angle, making calling elk easier. The Sentry Plate Single has a "Sound Plate" set at 16 degrees, which is perfect for cow, calf talk and spike bull bugles.Primos Hunting is Widely Known as the Premier Elk Calls and Elk Videos Brand on the MarketWill Primos' love for the high country shows through with the quality of elk calls that Primos continues to produce year after year. Primos elk calls come in many shapes, sizes, and sounds. When calling elk, being versatile is key; we have put years of recording and research into our calls.Primos Hunting: Speak the LanguagePrimos Hunting is the leader in the design and manufacturing of game calls for elk, deer, turkey, predator and waterfowl. Our commitment in game calls -- to make great products built by hunters, for hunters - also extends to our blinds, shooting accessories, trail cameras, attractants & supplements, clothes and other hunting accessories. You may also know us through our television show Primos' TRUTH About Hunting, DVD's and Mastering the Art video series.