Summary

250 screws, a random selection of "the most popular" smaller sizes for watch movements.

to see 1000 larger screws for watch cases, spectacles etc.

See an information article,

Will we have the size you want?

PLEASE do not send the measurements and ask us to look through the box and measure them. I did once try this, using a measuring microscope, and calculated that it could take many hours to find an exact match (there are thousands of screw types - length, diameter, head type, thread pitch...)

There are 500 screws, and they are the most common sizes for watches, and there is a fair chance that you will find the one you want (I have twice found just the right size for a watch I was repairing) ..but not guaranteed.

My best suggestion is: buy them, and if you don't find the screw you want this time, then maybe you'll find one for your next job.