The other seller claims "guaranteed authentic," but they also admit, "In the unlikely event it's a fake, we'll give you a full refund." This suggests they could be selling fakes at any time, and it's unclear what's actually genuine. This product is guaranteed authentic because it's a direct purchase from Kailh, and it's also cheaper than the other seller, so I highly recommend it. Super-speed shipping (= Nekopos) is incredibly fast. Recently, it's arrived from Tokyo to Kobe the next day. Speed shipping (= regular mail) takes 3 days even within Tokyo. Recently, there seem to be compatible products with the Kailh logo. How about the genuine Kailh click switch "KAILH MUTE Button" for silent mice, purchased from the official website? I'm selling these at a loss until the competition disappears, but I'm offering them at this price because I bought them in bulk. How about it for silencing or repairing your mouse? CMI627301 https://m.kailhswitch.com/info/kailh-silent-micro-switch-mi627301d-35964852.html I was able to repair the left click on my Logitech M331, so I'm introducing it and offering to sell these. You can easily find repair instructions by searching the internet. The following explains the M331 repair clearly: logicool 静音マウス M331の修理 (Repair of Logitech Silent Mouse M331) https://riku-zen.cocolog-nifty.com/blog001/2019/05/post-9d3d2b.html Other repair examples: Elecom EX-G, Logicool M510, M590, M570・M575, M650, M720, G700・G700S, MX Master Manufacturer: Kailh Mute Button Model Name: Silent Switch Wireless Mouse Button Micro Switch Size: 6*6*7.3mm Allowable Current: 50mA (A) Quantity: 5 pieces Please prepare solder wick if you need it. If you need it, I will reduce the number of switches by one and include about 6cm of solder wick. Please comment after winning the auction. By the way, it takes 2-3 weeks to arrive from Amazon, about a month. You could buy a new mouse in that time...