These jumprings are bright pops of colourful goodness, they are 10mm, 20 gauge in size. There are 50 pairs or 100 pieces give or take a few in each pack.  
 
They are a coated base metal and are the best quality I have been able to find.  When using ANY plated or coated jumprings we recommend using your fingers to open them - if your using them a lot and you would rather use pliers we recommend using flat needle nose pliers that are smooth.  Although the coating is good quality it will scratch when not handled correctly.
 
Colours may vary in batches so if you are restocking a colour keep that in mind and check your current stock before mixing the colours, its just possible there could be subtle differences.