If you need a complicated version, go with the Z15 Pro antminer or If you'd like a more cheaper miner go with the refurbished Z15 Han Su is usually a Complex Analyst at CryptoMinerBros, a leading provider of copyright mining components. He has around five yrs of working experience from https://open.substack.com/pub/antminer/p/is-it-worth-buying-used-asic-miners