2⅝"x 2⅝" flat metal lensboard with hole for mounting enlarging lenses with 39mm, 32.5mm or 25mm mounting thread on Beseler Printmaker and 67 series enlargers. The lensboards are not threaded - an appropriate retaining ring is required to mount the lens. The lens boards are used and may have cosmetic marks from previous use, but are in perfect working condition.