A CLOSER LOOKHome Improvement
A thinner seal for a smaller gap.
Frost King R338H Foam Weatherseal
Black · 3/8-inch-wide roll
Buyer feedback ↓Frost King’s self-stick rubber foam is a simple way to cushion a contact edge or close a measured gap. Choose the strip by its uncompressed profile, not by the cabinet name.
- 0.1875 × 0.375 inH × WMeasure the mounting surface; Test the door before sticking≈ 0.22 × 0.45 nickel diameters
- 10 ftStrip lengthCut to the gap you need≈ 10.9 Letter-sheet lengths
Amazon US · Black · 3/8-inch-wide roll · Retailer link
THE QUICK TAKE
Is it right for you?
Buy it for a simple cut-to-length seal on a suitable surface. The flat profile is easy to compare with the available gap, and the adhesive backing keeps installation straightforward. It is also useful as cushioning where surfaces meet.
Choose another profile if the door must compress the strip heavily to close. This rubber foam has limited compression. It also does not establish a safe humidity level or replace air circulation; sealing every opening is not automatically an improvement.
01 / BUYING NOTES
Before you buy.
Thickness decides whether it fits.
The foam has minimal compression. Measure the gap with the door in its normal closed position; an oversized strip can prevent the latch from closing.
Prepare before you stick.
The adhesive face needs a clean, dry surface. Cut the strip to your run and avoid stretching it during application. This is a gap seal, not a substitute for planned ventilation.
Material and profile selection ↗ · Exact roll dimensions and package ↗ · Installation demonstration ↗
02 / AMAZON REVIEWS
The buyers’ view.
Door-sealing results vary: one owner reports eliminating drafts and rattling, while another found only partial cold reduction and harder closing; an uneven door left another buyer with sections the strip could not reach. Buyers describe straightforward application, but adhesion drew mixed reports, including slipping after a few weeks. Removal can be frustrating: owners report torn pieces, with residue also reported.
What buyers like
- functionality88
- sealing26
- water resistance23
- cooling16
Mixed feedback
- quality85
- adhesion81
- Value for money60
- Durability36
The small numbers are review mentions. Topics and sentiment are from Amazon’s customer-review overview.
Amazon US · Checked . Ratings may include other colors and sizes.
View source ↗03 / REVIEWS & VIDEO
See it in use.
See how it works, then read the findings behind the buying advice.
How to Install Frost King Rubber Foam Weatherstripping
Frost King demonstrates preparing the surface and applying its self-stick rubber foam. The installation method covers the family; the pictured strip size is not established as this exact roll.
Watch on YouTube ↗Video and written sources are labeled by creator and tested scope. Manufacturer demonstrations explain use; they are not independent tests. No in-house hands-on testing is claimed.
Read source summaries Product scope is labeled · key findings in bold
The maker describes a self-stick rubber foam with minimal compression. That makes measured fit more important than expecting a thick strip to squash flat.
Frost King demonstrates preparing the surface and applying its self-stick rubber foam. The installation method covers the family; the pictured strip size is not established as this exact roll.
04 / COMPARE
Different priorities.
Choose the tradeoff that fits how you will use it.
Swipe to see every alternative →
THIS GUIDEFrost King R338H Foam WeathersealBlack rubber-foam roll |  ALTERNATIVEFrost King R734H Foam WeathersealBlack rubber-foam roll |  ALTERNATIVEDuck Small-Gap EPDM WeatherstripGray EPDM · small-gap profile | |
|---|---|---|---|
| Amazon price | $2.93 | $5.35 | $9.99 |
| Best for | A narrower, shallower measured gap | A wider, deeper measured gap | Small gaps needing a hollow profile |
| Design | Flat rubber foam | Flat rubber foam | Joined EPDM strips; separate to use |
| Use | Clean, dry surface before sticking | Clean, dry surface before sticking | Measure and test door closure |
| Consider | Too thin for a larger gap | Minimal compression; check closure | Different profile from flat foam |
| Explore | Read buying guide →Amazon source ↗ | Read buying guide →Amazon source ↗ | Read buying guide →Amazon source ↗ |
About these everyday comparisons
Approximate comparisons to familiar objects: a bank card’s 3.37-inch long edge, a Letter sheet’s 11-inch long edge, or a US nickel’s 21.21 mm diameter / 5 g weight. Water comparisons exclude the container’s weight. Capacity comparisons describe volume, not exterior size or how food fits. Reference pictures identify the object; use the labeled ratio for the comparison.
05 / PRICE HISTORY
The price over time.
Frost King R338H Foam Weatherseal · Black · 3/8-inch-wide roll · Amazon US
The chart legend identifies Amazon and new-offer prices when available. New offers can include marketplace sellers. Coupons, shipping and size/color selections can change the final price. Blank periods are missing observations, not a zero price.
06 / RELATED FINDS
A few useful extras.
For the way you plan to use it.
Watch the result
TempPro TP50 Hygrometer
A local humidity display helps show how the environment changes after sealing gaps.
Keep air moving
AC Infinity MULTIFAN S1
A separate USB fan provides local circulation when a shelf needs it.