Audio Technica ATH-M20 is the entry-level monitor headset of the Iron Triangle. Although the entry price is low, the sound quality of the M20 is generally considered good. Unilateral flip design can be used as monaural monitoring. However, monitoring earphones are mainly restored, so they may not be suitable for some people's listening feeling. However, this price is quite good for listening to music and watching movies.

The Audio Technica ATH-M20 recently dropped by 27.3 US dollars, about 165 yuan, and the price was about 230 yuan. Domestic Taobao is still at the pace of 400 yuan, and there is still a price advantage.