$12.56 = 4π
These socks show various periodic functions, as graphed on a cylinder, the way all periodic functions wish they were graphed. Specifically, they show the first few Fourier series approximations of a square wave.
Each order comes with one pair of socks.
Size Medium fits women's shoe sizes 6 to 9.5.
Size Large fits men's shoe sizes 8 to 12.5.