The 3D printed pocket pinger is a handy tool for checking coins and bullion, designed for use with an accompanying app(yes the app is free). Using frequency and resonance to verify the coin, or bullion these frequencies can't be faked... yet. This is a great tool to carry around with you to make quick, convenient and accurate verifications. Made in the United States, this portable device allows users to conveniently verify the authenticity and value of their coins on the go. Its compact size makes it easy to carry and use anywhere, making it a valuable tool for collectors and investors alike. Spend $10 today to save yourself thousands down the road. Available in orange, grey or about 60 other colors upon request. Thanks for looking