I am on my third field box. The first two were scratch built, number 1 was much too large and heavy, number 2 was smaller and lighter. When Sig came out with this one: http://sigmfg.com/cgi-bin/dpsmart.ex...FV5.html?E+Sig i couldn't pass it up and it has been very good for me. The removable "power" end is great when you are at events. You remove the end and that is all you need to take to the flight line.