Set of 8 bi-convex lenses with 50mm (5cm) diameter.  Set comprises of one each of the following focal lengths: 5, 10, 15, 20, 25, 30, 50 and 100cm (50, 100, 150, 200, 250, 300, 500 and 1000mm).

These are high quality, optically true lenses. Made of high quality polished glass and are spherical with round edges.