Go here: (place cursor over link, right click, select 'Open in new window')
http://database.ul.com/cgi-bin/ulweb/LI ... izard.html Click on 'Search for a Design that fits your needs' in the center of the page.
A 'Search Designs' menu opens, leave all options at their default settings, at 'Keyword Match' type in U341, then click 'Search'.
At "Search Results', click on the linked 'Fire-resistance Design No. U341 BXUV.U341.
Design U341 will open, scroll down to '2B. Gypsum Board*' through '2H. Gypsum Board*', there you will find the various manufacturers listed and the gypsum board they manufacture which is suitable for use for this design as the gypsum board listed as '2. Gypsum Board*'.
You will find Type X listed at most manufacturers, you will also find other options listed at some of the manufacturers. Most people generically think of all the options listed as 'Type X' even though there are options listed other than Type X.