You are getting a Vintage "NOS" 0-500 lb. in 5 lb. subdivisions Pressure Gage , Mfg. by Crosby Valve & Gage Company , Wrentham , Mass. It is panel mount  with a 1/4" male pipe thread bottom connection . The mounting flange is approximately 5 7/8" . The OD of the bezel is 5 3/8" . The bezel is removable . It threads on and if you look at the photos you can see that it is brass . It does not take to a magnet . The gage and bezel are painted black . There are (2) available but the one box does not have a label