Marco Lensmeter Marking Pin Holder Nuts are replacement parts for the Marco 101 Lensometer. L1-0158 Nuts are part of the lens inker or lens spotting assembly in the early model LM101 Marco Lensometer and serve to fasten the pin holder and align the pins. These nuts are reasonably simple to replace and do not usually necessitate recalibration of the lensometer. Replacement pin holder nuts are supplied in a set of 3. Please also see commonly replaced lensmeter parts: pins
, springs, and pin holders.