Keeler A.B.D.O. Pocket Rule Offers an interpupillary distance and measures distance between lenses Keeler A.B.D.O. Pocket Rule quantity Add to basket £49.00 Description Description Keeler A.B.D.O. Pocket Rule Offers an interpupillary distance and measures distance between lenses Designed to measure most specifications relating to spectacles. code 2299-P-1217