So say for example that the max fee is 15% and if Sarah requests to unbundle 100 bundle tokens into a 2020 GCO2. Here, the bundle token contract will automatically collect 15 GCO2 in fees account and 85 will be sent to the rake back contract. The rake back contract will contain logic on what the fee actually is; given that 2020 is a relatively recent vintage, but not the most recent, let's say the actual fee is 10%. So in this case the rakeback contract will pull 5 GCO2 back from the fees and send 90 GCO2 back to Sarah.