USCAMEL binoculars provide high-level outdoor performance, making them suitable for the avid birder or hunter. Magnesium Alloy Body: Lightweight, sturdy frame that will last a lifetime and handle use in the field. BAK4 Prisms with Phase and Dielectric Coating Glass. Right eyepiece diopter adjustment knob: there may be differences between the left and right eye vision,can be adjusted using the left eye clarity, then slightly rotate the right eyepiece diopter ring directly to achieve the best results. USCAMEL provides global after-sales service and high-quality products. If there is any dissatisfaction, there will be a 100% refund, guaranteed. This is your high-quality choice, and we look forward to your experience!