These battery trays were designed to make installing and removal of batteries quick and easy, No more fumbling with velcro straps in the air frame.
Secure bottom tray into airframe
Strap battery into tray
Slide battery tray into bottom tray 
turn hold down lever to secure in place and your good to go 
You can use either screws or glue to secure bottom tray, grooves have been incorporated into the bottom so the glue can get a good grip on the tray ( i recommend slow cure Hysol )
These are printed to order and usually ship within 48hrs.
Each tray comes with velcro straps.
Available colours are black, red, grey
Inside dimensions are 55mm x 75mm x 15mm
If you require a different size for a specific battery please contact me and i can make the size you require 
 
* If useing in a gas airframe please rember to check trays for loosness  do to vibrations form most gas engines