The Ballet is a simple device, which means not too much can go wrong. However, if you're entrusting your keys to it, you might be concerned about a couple of its design choices. The Ballet is made of 306 grade steel, which is less dense than the steel used in other physical wallets. 316 Marine Grade Steel is usually considered the best material for seed backup devices. Additionally, the public and private keys are printed onto stickers that are then stuck onto the steel, meaning the metal is doing nothing to ensure the physical integrity of your keys. Instead, you have to trust the plastic stickers with all your funds.