These are factory sealed, direct from Bitmain. Each miner includes a 365 day warranty from Bitmain, starting from when the miner ships to you.
Two C13 power cables (sold separately) carrying 220v power will be required for operation.
Bitmain sells its miners well in advance of being manufactured. A "May batch" preorder means the miner you are purchasing will be produced and shipped to you sometime in the month of May 2021. Due to shipping delays, preorder miners are often delivered as long as two weeks after manufacture date.