When hunting, we can't choose the weather. No matter how wet or cold it is, during the hunting season we have to head outdoors and ideally find prey.
In cold, damp air, however, the rifle scope's eyepiece lens can fog up. Then you, as a hunting enthusiast, can no longer see clearly through the target optics. It becomes impossible to release a safe shot. The fogging of lenses may occur with different frequency and intensity - depending on temperature, aiming position, breathing and clothing (scarves, for example, direct the breath towards the scope).
Extremely annoying - especially if you would have to shoot quickly. Even if the animal lingers, it might still take too long for the fogging to be gone.
Most people are right-handed and also shoot with their right hand. Depending on the firearm model, this often means that the bolt handle of the rifle is on the right side and gets rather close to the eyepiece of the scope when repeating. Therefore, the lid of the AFL must open to the left and the battery must be on the left side too. However, the AFL was designed to serve both left- and right-handed shooters. Left-handed hunters simply rotate the device by 180° before mounting it. The controls are then on the device’s bottom.