Prostaff P7 12x50 BinocularThe Nikon Prostaff P7 12x50 Binoculars adds a 12x50 model for increased light gathering and retains three improvements to the Prostaff top series: dielectric prism coatings increase the percentage of light reflected by the prisms, making the image brighter; a locking diopter which prevents the diopter from drifting once it is set for the user's eyesight; and an oil and water repellent coating on the external lens surfaces making the binoculars easier