EPDM rubber slide-out bulb seal with rigid C-channel featuring a domed interior that provides clearance for slide-out cables. Slides onto a track channel or wiper seal with track to seal against the RV body when the slide-out is closed. Protects against harsh weather and pests while keeping cables safely housed within the channel dome. Hand crafted and made in USA.
The Steele Rubber Products 90-3391-265 is a 15/16" high by 1-1/8" wide EPDM rubber bulb seal with a rigid C-channel featuring a domed interior profile. Like other C-channel bulb seals, it slides onto a track channel or wiper seal with track — no adhesive required — and its primary function is to seal against the RV body when the slide-out is retracted and closed, blocking rain, wind, road debris, and pests from entering the gap between the slide-out and the coach wall.
The defining characteristic of the domed channel design is its purpose-built cable accommodation. Where a standard flat-bottom C-channel seats flush against the track, the domed interior arches upward inside the channel, creating a protected cavity that provides clearance for electrical cables and wiring routed along the slide-out frame — preventing the channel from pinching, chafing, or compressing cables during retraction cycles. The 15 ft length is the smallest pre-cut option in this series, making it ideal for single-side replacement, top seal runs, profile verification before committing to a longer purchase, or replacing one damaged section of a domed-channel system. Commonly found on Entegra, Forest River, Heartland, Keystone, and Tiffin RVs.
Slides onto a track channel or wiper seal with track — no adhesive or fasteners required; secure mechanical retention through the full slide-out extension and retraction cycle
Arched dome inside the channel creates a protected cavity for electrical cables and wiring routed along the slide-out frame — prevents pinching and chafing during retraction
EPDM bulb compresses against the RV body when the slide-out is closed, blocking rain, wind, road debris, insects, and rodents from entering the coach
Covers one side or a full top seal run — also the cost-effective choice for confirming domed C-channel fit on your track before purchasing a longer 30 ft or 60 ft strip
The 90-3391-265 is known to fit the following RV brands, but compatibility is not guaranteed. Please verify your specific model’s specifications before purchasing. This is not an exhaustive list — other models may also use this profile. Commonly Found On: • Entegra • Forest River • Heartland • Keystone • Tiffin Compatible Track & Wiper Seal Systems: This bulb seal slides onto either a dedicated track channel or a wiper seal with integrated track. Compatible Steele Rubber track and wiper parts (sold separately): • 70-4120-265 — Track Channel • Wiper seals with track in Small, Medium, and Large sizes Profile Verification Use: The 15 ft strip is the practical starting point for confirming that the domed C-channel fits your specific wiper seal track before purchasing the 30 ft (90-3392-265) or 60 ft (90-3393-265) strip for a full or partial perimeter replacement. Related Bulb Seal Profiles (for size comparison): • 7/8" Bulb Weatherstrip with Channel — smaller profile • 1-3/16" Bulb Weatherstrip with Channel — larger profile Always measure the existing bulb seal height (15/16") and width (1-1/8") and confirm that your wiper seal or track channel accepts this C-channel profile before ordering. Actual fit may vary based on individual models, production years, and manufacturing variations.
The domed channel is specifically designed for slide-out systems with cables routed along the track. Before ordering, confirm the following: • Does your slide-out have cables routed near the bulb seal track? If cables run beneath or alongside the track, the domed channel is the correct choice — a flat-bottom channel could pinch or abrade wiring during retraction • Measure the existing seal: Confirm your existing seal matches the 15/16" H x 1-1/8" W profile before purchasing • Check track type: This seal fits both a dedicated track channel (70-4120-265) and a wiper seal with integrated track — confirm which system your slide-out uses • Confirm run length: A 15 ft strip covers one side of a standard single slide-out or a typical top seal run — measure the run before ordering to confirm this length is sufficient • No adhesive required: The C-channel slides onto the track mechanically — no surface preparation needed
Step-by-Step Installation: 1. Extend the Slide-Out: Fully extend the slide-out to access the bulb seal track and existing seal on the slide-out frame 2. Remove Old Bulb Seal: Slide the existing seal off the track channel or wiper seal track along the run being replaced 3. Inspect Track and Cables: Check the track channel for damage or debris. Note the routing of any cables — the domed channel is designed to clear these during installation and retraction 4. Cut to Length: Measure the run and cut the new seal to the required length using a sharp utility knife 5. Align C-Channel: Orient the domed side of the channel toward the track surface and align the channel opening with the track 6. Slide Onto Track: Starting at one end, slide the C-channel onto the track, working steadily along the full run 7. Seat Fully: Confirm the C-channel is fully engaged on the track with no lifting or partial seating along the length 8. Retract and Test: Retract the slide-out and inspect the seal contact line against the RV wall — the bulb should compress evenly with no gaps. Confirm cables are clear and uncompressed inside the dome 9. Inspect End Joints: Where this strip meets any adjoining seal run, confirm the joint is snug with no gap
In The Package: • One (1) continuous 15 ft strip of 90-3391-265 EPDM Bulb Seal With Domed C-Channel Recommended Companion Parts (Sold Separately): • 70-4120-265 — Track Channel (if replacing or adding a dedicated track) • Wiper Seal With Track (Small, Medium, or Large — if replacing the full system) • 90-3392-265 — Same Profile, 30 Ft (for two-to-three-side replacement) • 90-3393-265 — Same Profile, 60 Ft (for full perimeter replacement) Recommended Tools (Not Included): • Sharp utility knife for cutting seal to length • Tape measure for measuring the slide-out run • Flat blunt tool for seating the C-channel onto the track in tight sections
This bulb seal is available in four options to match the job size: By the Foot: For replacing a short damaged section or spot-checking domed C-channel fit before any further purchase 15 Ft Strip (This Item): Covers one side of a standard single slide-out or a full top seal run. The best option for single-side replacement, top-seal-only jobs, and fit verification before ordering a longer strip 30 Ft Strip (90-3392-265): Covers two to three sides of a standard single slide-out. Use when the top and one or two side runs need replacing together 60 Ft Strip (90-3393-265): Full-perimeter coverage for large single slide-outs or two sides of a dual slide-out. Minimizes field joints for the most consistent seal Tip: If you are unsure whether the domed C-channel fits your specific wiper seal track, start with the 15 ft strip to verify fit and cover any single-side repair before committing to a longer roll. Most standard single slide-out top runs fall within the 10–15 ft range, making this strip the right size for a top-seal-only upgrade.
The domed channel is a purpose-engineered feature for slide-out systems where electrical cables or wiring harnesses run along the frame beneath the bulb seal track. At 15 ft, this strip is the right starting point for a single-side repair, a top-seal-only upgrade, or profile and fit verification — and the same domed channel profile is available in 30 ft and 60 ft lengths when a more extensive replacement is needed.