The thread is 100% mercerized cotton, each ball is 50 g or 1 3/4 oz.  Recommended needle sizes:  Knitting Needles 00/1 Crochet Hook 0A/18. 

No size is listed, but it looks like about the same weight as #5 Perl cotton. It has a very nice shiny finish. 

The balls are in excellent condition, complete  with the original wrapper. They have been stored in a non smoking household.

Thanks for looking and Happy eBaying.