The Particle LIITA Bridge was developed to enable you to transfer your Banksy Love is in the Air Particles from the Avalanche network to Ethereum Mainnet.
A transactional fee in AVAX on the Avalanche side of the transaction is necessary to complete the transfer of Particles to Ethereum. The fees on the Ethereum side are covered by Particle. This fee covers the cost of gas for completing the bridging transaction.
Once your LIITA Particles are transferred onto the Ethereum network, you cannot bridge them back to Avalanche. All bridging transactions are final.