This is the O Scale Surface Details Freight Car Rivets from archer fine transfers.
Sheet contains 112 linear inches (285 cm) of 3-dimensional resin rivets .016 inch (.41 mm) in diameter spaced .116 inch (2.95 mm) apart vertically and .093 inch (2.36 mm) horizontally on clear decal film. Comes with instructions.
Archer Product Number: 88034
Walthers Product Number: 108-88034
Actual sheet size is 2.75 x 4.5 inches (7 cm x 11.4 cm).