A plano convex lens fits exactly into a plano concave lens.Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive index u1 and u2 and
Dia25.4mm EFL100mm C7980-0F Plano Concave Lens Uncoated, 1104-031
Plano - Concave Lenses
N-BK7 Plano-Convex Lenses (AR Coating: 1050 - 1700 nm)