I have had this mouse for almost 2 years and never knew what this button under my scroll wheel did. I thought it wasn't binded to anything since nothing happened when I pressed (or so I thought) so I just forgot about it. I would press it on accident or just do it mindlessly sometimes.

When I started playing Valorant I noticed that sometimes my sens felt off sometimes and I never knew why. I played like this since beta and it wasn't till today I realized that that button changes my dpi of my mouse SUPER noticeably. I don't know how I didn't think of this or notice it until I tested it. I don't think it effected my skill that much because I hardly even noticed it, but it still annoys me lol.