Sony A700 4x5 The B+W NL2 is a

The B+W NL2 is a high quality +2 diopter attachment for lenses with a 49mm front filter thread

with 3/8" threads top and bottom

It also has interchangeable lenses

film or digital- but not Sony mirrorless cameras (that's a different mount)

Sony A700 4x5 The B+W NL2 is aThe Sony A550 is a DSLR camera with a 14mp APS C sensor and a clever hybrid optical EVF system you can change up with the flip of a switch. It's kind of neat! This camera is compatible with any Sony DSLR and Minolta Maxxum lens, but it's not compatible with any Sony mirrorless lenses that's a different mount, despite sharing the "alpha" designation. Includes battery, charger, CF card, and strap.