Green Polka Dot Derbies (1 Dozen) by CarnivalSource.com! Get noticed with this funny hat. Each derby hat comes with vibrant colored polka dots. The perfect hat for feeling light hearted and goofy at any event! Find more great items like this in our St. Patrick's Day Party Supplies category here at CarnivalSource.com. Green Polka Dot Derbies (1 Dozen) are fun and playful hats for any event. Each derby hat is made of plastic and has a vibrant green polka dot design. The inside circumference is 23 inches and outside hat dimensions are 10 1/4 inches long x 9 inches wide x 3 3/4 inches One size fits most and it is suitable for ages 3 yrs.+. Assorted colors make it a great choice for St. Patrick's Day Party Supplies. Ships from Missouri warehouse within one business day. 12 PC in Poly Bag.