Trifold Measures...19.5" long (7" closed) and 9" tall. It has 3 compartments.  1st has 2 strips of 1" elastic to hold items such as flight computer or notepad.  Elastic is 4" from top to bottom, with 3" in the middle.  The backside of this compartment is a single clear plastic pocket, 5" x 6".  In between compartment 1 and 2 is a removable document loops.  Middle has your removable clipboard and clear plastic pocket.  Pocket Measures 5" x 6.5"  Pocket behind clipboard measures "6 x 7.5".  Between middle and 3rd compartment is a 6.5" x 1" Hoop Velcro strip.  You can place anything here like another doc. loop.  3rd compartment is a single clear plastic pocket 4.5" x 7.5".  Outside has your attached adjustable legstrap with plastic buckle.
All our Kneeboards are made of Cordura fabric.  A frabric that is water and mold resistant, fire resistant and extra durable.  We double stitch all the edges, for added durability.  The Plastic is also a higher quality to withstand tears and gashes