What You're Looking At
This is a sealed oval LED combo light — stop, turn, and tail all in one lens, running 6-3/8 inches long. That size and shape is basically an industry standard at this point, which is why it shows up on trailers from a dozen different builders, plus plenty of straight trucks and service bodies.
Comes as a kit, so you're getting the light itself, not just a bare lens. Grommet-mount style is typical for this oval — check if yours is grommet or stud-mount before you order, because that's the one thing that trips people up more than the electrical side.
Being LED, it draws less current than the old incandescent ovals and doesn't burn through bulbs, but the plug/pigtail config still needs to match what you're pulling off the truck or trailer.
Why F01821S125 Crosses to Grote 54172
Grote's been building this exact oval shape and lens pattern for years, and a lot of aftermarket houses build to that same footprint because it's what half the trailer OEMs spec'd off. That's why F01821S125 and Grote 54172 line up — same size, same mounting circle, same general light pattern.
What doesn't always cross clean: wire color coding and connector type. Some ovals use a 3-wire pigtail, others 2-wire with grounded housing. Pull the old light and check the plug before you assume the new one just plugs in.
If the number on your old light doesn't match either of these exactly, don't panic — oval lights get relabeled by a dozen private brands. Match the physical dimensions and grommet type first, then confirm the wiring.
Ordering From PartStop
We're in Tacoma, so if you're local and need it same day, call ahead and we'll have it at the counter. Otherwise it ships out same or next business day anywhere in the country.
Surest way to make sure this is the right light: pull the old one and read whatever number's stamped on the lens or housing, or just grab your VIN if it's a factory-installed application, and we'll match it up before it leaves the shelf.
Backed by our standard 6+ month warranty — if it's DOA or fails early, bring it back or call, we'll sort it out. No guessing games, no return-it-and-hope situations.
PS-EL.01.UN.013 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to PS-EL.01.UN.013. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| OE | F01821S125 |
| Grote | 54172 |
Frequently asked questions
Does F01821S125 fit my utility trailer?
Depends on what oval light is on there now. If it's a 6-3/8" oval with the same grommet mount, it'll likely work, but confirm by measuring the old lens or checking the number stamped on it before ordering.
Is this the same as the Grote 54172?
Same size and mounting pattern, so it crosses over for most applications. Wiring pigtail can differ between brands though, so check your connector type before assuming plug-and-play.
Can I use this to replace an incandescent oval light with LED?
Yes, as long as the physical mount matches — the LED version pulls less amperage so it won't overload your circuit, but you do need to verify your trailer's flasher/module is LED-compatible, especially if it's an older analog flasher unit.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.