True Freeze is an autonomous protocol allowing anyone to lock ETH out of circulation ("proof of patience") and mint frETH yield tokens and a tradeable Certificate of Deposit Freezer NFT for doing so. You lock WETH for anywhere between 1 day and 1,100 days. This puts ETH into the future, removing it from circulation. In exchange for this, you mint freezer-ETH (frETH) yield tokens and get a Certificate of Deposit Freezer NFT. When the NFT matures, it can be redeemed at no cost for the underlying WETH (i.e., you keep the frETH you got paid upfront). Redeeming the NFT prior to its maturity date requires fees. The fees are paid to stakers of the Freezer Revenue Token (FRZ).

Freezer NFTs are Certificates of Deposit. Each NFT is backed 1:1 with WETH locked in the system. These NFTs can be sold on any NFT marketplace (e.g., X2Y2) transferring ownership of the locked WETH with it.