You send: Wrapped Bitcoin (Arbitrum One)
Wrapped Bitcoin (WBTC) is an ERC20 token backed one to one by bitcoin held in custody, made to bring BTC into Ethereum applications. Its value tracks BTC; its address format, network and fees are Ethereum's. More about Wrapped Bitcoin.
On this pair it moves over Arbitrum — an address there starts with 0x — 42 characters.
WBTC also exists on other networks — different addresses, not interchangeable: ERC20, Optimism, Polygon, Solana.


