A few minutes spent finding the right number before you call saves everyone time at the counter.
The fastest way to get the right part the first time is to have the part number in hand before you call or come in. Here's where to look depending on what you're replacing.
Most brake chambers are stamped with a manufacturer code and size on the housing itself, usually near the clamp band or on the flat face of the can. On brake shoe kits, check the shoe casting for a part number, and note the drum diameter and lining width, that's usually enough for us to cross-reference the right kit even if the stamped number is worn.
LED stop, tail and turn lights usually have the part number printed on the back of the housing or on the connector itself. If it's worn off, a photo of the light along with the shape (oval or round) and whether it's stop/tail/turn or a combination light is enough for us to match it.
For coiled air lines and 7-way cables, the length and connector style matter more than a stamped number, most of these don't carry a visible part number at all. Measure the coil length extended and note the fitting type (bayonet vs. threaded) before you call.
Fleetguard and other filter brands print the part number directly on the filter housing or the box, if you still have it. If not, your engine's make, model and year (for example, a Cummins ISX) is enough for us to look up the correct fuel, oil or fuel/water separator filter.
Don't worry about it. The make and model of the truck or trailer and a description of what's failing gets our counter team most of the way there. See our parts and categories page for a look at what we stock, or call the counter and we'll help you narrow it down.