Specialized hardware for mining cryptocurrencies.  An ASIC miner is a stand-alone device that is a self-contained unit containing the proof-of-work (PoW) blockchain software, typically Bitcoin.  It is designed to plug into the Internet and start mining.  Another variety of crypto mining hardware is the GPU (see 
GPU mining rig).  See 
ASIC farm, 
miner hardware, 
crypto mining, 
ASIC resistant, 
Bitmain and 
Bonanza Mine.