Small Vertical Reference Floor Window Kit - Sliding Door CompatibleDART Vertical Reference Floor Window Kits are available in three sizes to meet a variety of operational needs. You may now easily see through the floor window for vertical reference flying. Since the wider windows allow you to view further up the line, you can choose a shorter line, increasing your operational options. The huge outside windows are installed in the AFT panel using 1 4" fasteners that may be readily disassembled for maintenance. The