This is a pair of vintage Official Roller Derby roller skates for a youth. I am unsure of the exact size but I wore them when I was 7 years old.  They have the iconic color scheme of white with red and blue accents.  The wheels state Fireball.  They were all the glory in the days! They even come with the nostalgic vintage smell.  
They are in good shape but show some scuffs and maybe grime build up.  These were worn in the early 1970's and are a true collector item!  
See photos for actual condition. Ask if you have questions!   
Thank you.