..and an old canvas canteen bag or other type of bag with the belt straps sewed in. You can get them at Army surplus stores. Or, try looking for the newer nylon type bags. The belt straps on these bags are large, and the web belts or nylon belts you can find at the home stores fit easily through them. Also, Whites has a bag for these machines ( I have one from my BHID300)
I bought 2 of the canvas bags for 6 bucks a piece at my nearest Army surplus store for using my CZ6a. The main problem if you are going to use if for the PI Pro or Dual Field is you have to cut the bottom so it makes a flap. This is because the box and cable are hard wired. Put the unit in, from the bottom, starting with the headphones, and them sew up the bottom with fishing line and just leave a small hole for the cable. The bags I bought have the top flap able to shut close and lock in ( some use a snap..this one has something similar to a button).
Anyway...there are lots of ways. The Husky belt costs the most but it is really nice. Padded, with a slightly larger back to support your lower back and it has velcro and 2 hole gromets. See pics.
Hope this helps.
JC