Because the lens stage on Beseler 45MXT and 45VXL enlargers was redesigned to accept the 3-lens turret, these models require a different under lens filter holder than is used on the older models. This filter holder assembly is designed specifically for use on the 45MXT, 45V-XL, 810MXT, and 810V-XL enlargers only. The filter holder can be adjusted vertically on the post so it can be positioned as close to the lens as possible. All metal construction. Includes securing nut and lockwasher.