The sUSD bridge extension of the ETH-xDai Arbitrary Message Bridge is a pair of mediator contracts (similar to the ones used here) allowing the user to transfer Synth sUSD from the Ethereum Mainnet to the xDai chain and back.
Mediator contract at Ethereum Mainnet:
Mediator contract at xDai chain:
This extension was deployed to demonstrate a working model of the ETH-xDai AMB. Anyone who owns sUSD tokens can use the bridge - sUSDs are locked in the bridge contract and the same amount of sUSD bridgeable tokens are minted on the xDai chain. The reverse operation burns sUSD bridgeable tokens on the xDai chain and unlock Synth sUSD tokens on the Ethereum Mainnet.