Rapid Rivets Antique Nickel Medium 3/8" Head 200 Pcs Great looking Antique Nickel Finish Steel Double Cap (for a nice finished look on both sides). This lot: 200 tops, 200 bottoms. 5/16" post (finishes to about 1/4" height); 3/8" diameter head (most popular all-around size). Easy to use- Quick pop with soft mallet hammer for good secure closure.