A six-inch oval trailer lamp is not automatically interchangeable with another six-inch oval. Optronics makes recessed grommet, surface-flange and recessed-flange lighting with different connectors, depth and included parts. Identify the original installation before comparing the exact models below.
Three mounting styles to tell apart
Recessed grommet
A separate rubber grommet holds the oval body in a cutout. Examples include ST70 and the STL12 lights in the TLL12RK kit.
Surface flange
The lamp flange attaches to the panel face without the usual recessed lamp-sized opening. The STL73 family uses this arrangement.
Recessed flange
A flange is visible on the outside, but the lamp body still needs a corresponding recess. STL111RFB is one such design.
Simplified orientation graphics, not manufacturer scale profiles or drilling templates.
Check the grommet opening: Optronics specifies a 6.85 × 2.50-inch rounded opening with 1.25-inch corner radius for its A70GB grommet. This dimension does not apply to surface-flange lamps. Verify the original grommet, panel and clearance before cutting.
Six-inch oval Optronics comparison chart
| Part | Mounting | Function | Connection | Approx. W × H × D |
|---|---|---|---|---|
| ST70RBP | Recessed grommet | Incandescent stop, turn and tail | PL-3 plug | 6.50 × 2.313 × 2.375 in |
| TLL12RK | Recessed grommet | Two six-LED stop, turn and tail lamps | PL-3 plugs | Each 6.50 × 2.25 × 1.75 in |
| STL75AB | Recessed grommet | Amber side turn and marker | PL-3 plug | 6.50 × 2.313 × 2.75 in |
| STL73RBP | Surface flange | Six-LED stop, turn and tail | Hardwired leads | 7.563 × 3.313 × 0.75 in |
| STL73RK | Surface flange | Six-LED stop, turn and tail | Hardwired leads | Lamp as STL73 family; chrome cover adds trim |
| STL1211RCFHPGP | Surface flange | Stop, turn, tail and backup | Dual female PL-3 connectors | 7.50 × 3.25 × 1.01 in |
| STL111RFB | Recessed flange | 22-LED GloLight stop, turn and tail | PL-3 plug | 7.50 × 3.30 × 1.938 in |
| A78RXBP | Reflex trim | Red snap-on reflector ring | None | Check flange profile |
Measurements are in inches and refer to individual lamp housings, not retail kit packages or optional trim. Confirm the full flange and wiring at installation.
Five checks before ordering a replacement
- Inspect the old light's rear mounting surface, panel opening and available depth.
- Identify a standard PL-3 three-pin connector, hardwired leads, or additional circuits for backup lighting.
- Confirm lighting function. An amber side marker/turn light is not a red rear stop/turn/tail lamp.
- Check whether the listing is lamp-only, a pair with grommets and plugs, or an accessory trim ring.
- Use the original MPN and product image to confirm shape and supplied components.
Wiring differs by family: STL73RBP/RK have red stop/turn, black tail and white ground leads. ST70RBP and TLL12RK use PL-3 connections. The clear-lens Fusion combination light adds backup lighting and must be matched to the proper circuits.
Compare parts and product photographs
Recessed grommet lamp options
Optronics ST70RBP — Incandescent stop, turn and tailLamp only; grommet and pigtail are separate.View product and availability
Optronics TLL12RK — Two six-LED stop, turn and tail lampsTwo STL12RB lamps, two A70GB grommets and two A45PB pigtails.View product and availability
Optronics STL75AB — Amber side turn and markerE2-rated nine-LED side light; not a red rear stop/tail lamp.View product and availability
Surface flange lamp options
Optronics STL73RBP — Six-LED stop, turn and tailRed stop/turn, black tail, white ground. Light only.View product and availability
Optronics STL73RK — Six-LED stop, turn and tailRetail kit with A78CB1 chrome snap-on cover.View product and availability
Optronics STL1211RCFHPGP — Stop, turn, tail and backupClear-lens 22-LED Fusion; includes a reverse-light function.View product and availability
Recessed flange lamp options
Optronics STL111RFB — 22-LED GloLight stop, turn and tailRecessed body with surrounding flange; check the panel opening.View product and availability
Reflex trim only
Optronics A78RXBP — Red snap-on reflector ringTrim only, not a lamp; for specified surface-flange models.View product and availability
Manufacturer references: ST70 family, STL12 family, STL73 family.
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