Anti-siphons install easily in most HD & MD diesel fuel tanks, including buses. Anti-siphon devices are less expensive than locking fuel caps and provide top notch security and theft protection. Anti-siphons can be installed in as little as 15 seconds and provide a lifetime of fuel theft prevention. Once installed the anti-siphon device cannot be removed. It cannot be broken out or taken out by fuel thieves. Patented and quality built in the USA, there are already over 450,000 in use!
Measurements to determine type of Anti-siphon
Inside Diameter (A) of Fuel Tank Fill Neck in Inches
Length (B) of Fuel Tank Fill Neck in Inches

Anti-siphons are easy to install and
extremely secure.
| Part # |
Diameter |
Length |
Intended for use with |
 |
| ATW 3-7 |
3.00” |
7.0” |
Volvo, Mack, and International |
| ATW 25-675 |
2.50" |
6.75" |
Volvo, Mack, and International |
| ATW 25-95 |
2.50" |
9.5" |
Kenworth |
| ATW 2-7K |
2.00" |
7.0" |
Kenworth |
| ATW 225-95 |
2.25" |
9.5" |
Freightliner |
| AWT 187-75 |
1.875" |
7.0" |
Medium duty Internationals & reefer units with 1.875” I.D. |
| ATW 2-7 |
2.00" |
7.0" |
Freightliner M2 & Medium duty units with 2” I.D. |
| ATW 4-9 |
4.00" |
9.0" |
Units with a 4” fill neck |
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Measurements are based on the inside diameter (I.D.) of the fuel tank neck.
Anti-siphons do not restrict fueling or cause splash-back.
Anti-siphons are not made for gasoline tanks. DIESEL TANKS ONLY!!!
There are no Anti-siphons for Peterbilt fuel tanks, construction, or farm equipment.