Countries: 166

Athletes: 4,200

Sports: Archery, boccia, cycling, equestrian, football, goalball, judo, powerlifting, rowing, sailing, shooting, swimming, table tennis, track and field, sitting volleyball, wheelchair basketball, wheelchair fencing, wheelchair rugby, wheelchair tennis.

Classifications: There are different levels of "eligible impairment types" that vary from sport to sport and are determined by an international panel.

TV: NBC Sports Network will have one-hour highlight shows at 6 p.m. on Sept. 4, 5, 6 and 11. NBC (Ch. 11) will have a 90-minute special at 1 p.m. on Sept. 16.

History: The Paralympics started in Rome in 1960. They were opened to non-wheelchair athletes starting in 1976, the same year the Winter Paralympics started.

Websites: paralympic.org; london2012.com/paralympics/

Twitter: @paralympic