These binoculars feature 8X magnification with an objective diameter of 25mm. The SI Series twist-up/down eyecups work for eyeglass wearers or those without glasses. Simply twist-down the eyecups if wearing eyeglasses, and twist-up for non-eyeglass wearers to find perfect eye relief. These binoculars are sealed to provide 100% protection from rain, snow, or humidity. Charged with nitrogen gas, these binoculars prevent fogging and internal water buildup.