Fog is a constant issue for a lot of airsofters. There are a lot of methods for helping with fog but the most reliable method for anti fogging is forcing fresh air into the goggles using a fan. This is especially important for those of us who wear prescription lenses. This kit is one of the best we have found. The fans make minimal noise and vibration making them a haven for people who have used fan goggles that feel like you are wearing a freight train on your face. They are assembled in Canada and come with a 1 year warranty.
This fan kit lasts approximately 12 hours on one high quality 9v battery. Also compatible with rechargeable 9v batteries.