Approximately 1/2" dia. x 3/16" thick. Strong mid-sized magnets at a surplus price. Notice in the lower picture on the left that the South pole is marked with a red stripe on each magnet.
These magnets are sold in packs of 10. Order a quantity of 1 and get 10 magnets. Order a quantity of 2 and get 20 magnets. Order a quantity of 3 and get 30...