The Chrosziel 411-15 is a step down adapter ring. When the outside diameter of a professional camera lens is 62mm, the user needs a step-down ring to adapt the 4x4" sunshade. This step-down ring adapts from 104mm 4x4" Chrosziel sunshades, such as the 411-50, to cameras with 62mm lens opening, such as the Sony HVR-V1.