There are two important parameters in the creation of a Tunnel: pledging coefficient (k) and commission rate (m, n). In version 1, the pledge coefficient k of the tunnel is kept at 50-100%, while the commission rate for minting as well as redemption are both set at 0.2%, and the minting section requires extra network fees. In version 2, however, we aim to let tunnel operators decide on the pledging coefficient and commission rate. The pledge coefficient is abstract, and it is only used as a system parameter. Usually, BoringDAO tunnel uses Asset Ratio to describe oToken. For example, when pledge coefficient is 50%, it means that each oBTC is backed by 1 BTC + 0.5 BTC equivalent of ERC-20 assets, and the oBTC Asset Ratio should be 150% (100%+50%).