Engraved bezel and crosshairs allow clock hour estimation in neo-vascularization when viewing ROP. Estimate the size of inflammatory/non-inflammatory retinal lesions. Grid spacing aids in estimating the size of ocular tumors. Bezel is conveniently marked at hour and half hour locations. Designed to fit anterior side of Ocular 28D Indirect Lenses.* The Ocular 28D Indirect Lenses are sold separately. *Lens design with diamond knurl pattern only