S.M.S.L power amplifier, the S.M.S.L AO100. SMSL, which releases similar new products frequently. This unit received good reviews, but due to the rising cost of parts, sales were discontinued early. The similar A100, released at the same time, remains in the lineup. Regarding the differences from the A100, according to AI: "The main differences between the SMSL A100 and AO100 are that the A100 specializes in Bluetooth connectivity and subwoofer output, while the AO100 has more functions such as a display, remote control operation, and equalizer functions. Both models are equipped with the Infineon MA12070 chip, achieving high sound quality and high efficiency." ↑ This was the response, but I think the biggest difference is the presence or absence of USB input, as both have subwoofer output and Bluetooth. This unit does not have USB input, but instead allows for various operations via remote control. Remote control is surprisingly rare in this class. It may have slight dirt from use, but it's in good condition. Original box and accessories are included. I've attached a Hi-Res sticker. Immediate purchase is welcome, and I will ship it no later than the next day. Thank you. RCA, Bluetooth input With remote control Inputs: RCA, BT Output power: 70W x 2 (4Ω) Power consumption: 36W Standby power: 0.5W Volume: W150 x H39 x D128mm Weight: 560g Thank you for viewing.