Metal Project Box. The base is about 1-1/2" x 1-1/2" square shape. The cover will have 2 screws as shown and some may have one screw on the bottom side. This box has a BNC female and may have some other electronic components on the inside that can be removed. The BNC female is a short female and may not mate with a normal BNC male so you might want to toss out the BNC and put a connector of choice if desired.  This box has a banana jack set as well. There will be one or two solder tabs (two holes shown) on the bottom.  They are well made and feel nice and substantial being real vintage metal. The paint tends to flake off some but it is a easy clean up and repaint to a desired color. These are really nice metal boxes, I've used several of these for some of my test gear projects and they work dandy.