DIESEL Keeper ASD A Series 3 Anti-Siphon Device that fits on the diesel tank inlet of most Heavy Duty Freightliner Class 8 built during or after 1996 where the tank inlet is at least 2.25" ID and at least 4.75" deep to allow for the fitting of the ASD™.

The top grid has a honeycomb shape inside the fill neck, and the bottom grid has a similarly shaped honeycomb shape, but on a slightly smaller grid.  Both grids allow for a dipstick to gain access to the tank for mauel fuel level verificaiton and for DOT inspections.

The top flange is about 2.5" wide and has fifteen trapezium openings grouped in three sections of three each around the circumference of the neck. These opening are to allow for air to escape as the tank is filled. At the bottom of the device there are three flow slots on the inner sleeve and two cutouts on the outer sleevers. The outer sleeve comes all the way down the unit and has a total of six security arms that are manually pulled out to about 30° with a narrow screwdriver prior to installation.

The Device comes with a built in filler neck extension. The device is about 4.6" inches tall when in its "resting position", it is about 6.375" tall with the filler neck extention at the half way resting place, and about 7.5" tall with the filler neck extention at its fully extended position. 

The Device is designed to fit into the diesel tank with the top being just about flush with the diesel tanks steel lip that can be found underneath the diesel cap. One can continue to use the machines existing diesel cap. Any diesel screen below the diesel cap would need to be removed to allow for fitting and installation of the unit.