Trekker USA Anti Siphons are manufactured to prevent fuel theft from heavy-duty truck fuel tanks. They fit most all over-the-road fuel tanks using 1.85- to 3-inch ID
necks, including Volvo, Mack, International, Freightliner, Kenworth and reefer tanks. Much less expensive and more secure than a locking fuel cap, the maker says. And they install in less than 30 seconds. Call 541-910-0773.