This item is a new product promotional brochure for the  Eitel-McCullough, Inc., Eimac A4CX300A Ceramic Power Tetrode  (tube). It is 8 1/2" x 11" and has 3 holes for binder storage. It consists of two sheets, 4-sides with info on all four sides. Info includes descriptive text, general characteristics chart, graphs, and Tentative Data.  I can't find a date on it but it has to be from the mid 1950's period.  Excellent condition.