I've learned that if the router or modem lasts more than 3 years, the cost of the fans is worth it. I ALWAYS buy my telecom equipment, not rent it. I've invested in a good Asus AC88U router so I wanted it to stay cool so it wouldn't freeze. I haven't done this before and my router usually fails after 2-4 years. Talking about crashes, they don't die, they just start doing weird things, then I reset and flash, and after a short while the device starts behaving strangely, freezes, stops transmitting packets, etc. There've been i invested In this outfit it is an easy choice. First let me say they use a laptop style fan and it's nice that they also include a switch to adjust speed/noise. I found it worked 80% for me with minimal noise. 100% louder than we'd like, but when it's close what's the difference? My unit doesn't seem to get 80% hot so I'll try and adjust as needed. The fan assembly matches the router perfectly, so much so that I doubt anyone will even know it's aftermarket unless they have the exact same router. It's very easy to install, 2 clips lock it when you slide it forward and that's all you need. I also purchased an acrylic base with two fans, which I will forgo as this single fan seems to work great on its own. I paid over $300 when this router came out. So if I can last 5+ years just by adding fans, it's a worthwhile investment. I also use a fan on my modem that gets hotter than a router. I have a Motorola SB-6190 and the fan I got (from Revain) is the device: https://www.amazon.com/gp/product/B01M5BBD9K/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Das works well too, remember to blow it out once a year. I would assume the same applies to this router fan.