1.75" Die Struck 3D Challenge Coin Solid Brass! Officially Licensed product with Coins For Anything, Inc. True Challenge Coin! Designed By Marines FOR Marines! E8 Marine Corps Rank Challenge Coin! Master Sergeant E8. This coin is 1.75" Antique Brass with color on both sides! Nice addition to any collection! This custom coin is an officially licensed product with the USMC under Coins For Anything, Inc. This design was created for Marines BY Marines!