This is an assortment of vintage optical eye test lenses, the great grandfather of the ones that the optometrist turns and says "which is better, one or two". There are different thicknesses, most have numbers and are marked with a negative or positive sign. If you'd like a specific lens, please let us know in your order and we'll do our best to get the ones you want depending on what's left. Approx 2 inches across including handle.