An application-specific integrated circuit (ASIC) is a chip customized for mining, rather than intended for general-purpose use (such as GPU). Such a device may provide much better mining performance than GPU.
The Innosilicon A4+ LTCMaster was produced by Innosilicon and released in 2017. This miner consumes 750W, producing 620.0 Mh/s of hashrate with the scrypt algorithm, which makes this device almost (if not at all) useless. We do not recommend buying this device for mining nowadays.
For more details, visit the official website innosilicon.com.