Step Up Ring 43-49mm Instant Film Multigrade filters are supplied in

Multigrade filters are supplied in 3 inch  by 3 inch square sizes to fit most enlarger's filter drawers

then the lens will only be an f/2

Just take the lid off and drop in your film

The optical construction features 9 elements in 6 groups

Step Up Ring 43-49mm Instant Film Multigrade filters are supplied inStep up rings are used when you need to mount a filter that's larger than the diameter of your lens barrel. The first number refers to the barrel size, and the second number indicates the filter size that will fit on the ring. Step up rings are a great way to save money on filters, since instead of having to buy several different sizes of filters for your various lenses, you can buy just one large filter and several inexpensive step up rings instead.