The Emerson "wave shaped opening feature" is a fast, effective, and impressive way to open your knife. The patented Emerson "wave shaped feature," a small wave-shaped tab on the top of the blade that's built to catch on your pocket seam, opens the knife as you withdraw it from your pocket. This instant-open feature is a favorite among military, rescue, and law enforcement knife users. But it does take a little practice. Enter the Kershaw-Emerson E-Train, the “Emerson trainer” knife. The blade is unsharpened so you can safely practice using the “wave shaped opening feature” without endangering either your pocket or your fingers. The E-Train’s G-10 front scale is in “safe-training blue” for easy identification. There's a left/right reversible pocketclip so you can easily carry it with you to train whenever you have a spare moment.