The SitSpots 30 Circle Pack consists of the following: 5 circles each in Blue, Bright Green, Orange, Purple, Red, and Yellow. These original SitSpots adhere to glued down carpeting by means of attaching themselves to the carpeting without adhesives. They're made from an industrial strength material that outperforms all other types of similar material for durability and longevity. They work on some but not all area rugs. SitSpots can be safely vacuumed over, are washable and reusable, and can be used for classroom management and interactive floor games. SitSpots, are the perfect size for your classroom, 4" in diameter! This size was selected based on performance testing in the classrooms of young children: The 4-inch size fit completely underneath seated student bottoms and prevented most students from pulling at, fraying, and ruining the Sit Spots The larger sized (5 and 6 inch) Sit Spots had a tendency to tear when removed from the carpeting and deteriorated prematurely from students pulling at and fraying the edges. Visual cues were not compromised using the 4 inch sized Sit Spots.