I've just be given an Opemus III enlarger which I've set up and started to used with pleasing results. It takes a pearl/opal 100w 'philips' bulb ( screw fitting ) according to the instructions from Meopta. I was worried about getting replacements but I found that 'woolworth' pearl bulbs are the same size and diameter. The writing on the top came off very easily without removing any opacity. I'm sure you will be able to find an equivalent spare. I was a bit sceptical about using the Opemus III but with some cut down multigrade filters in the draw it works a treat. Enjoy it.