---
product_id: 16882158
title: "Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch"
brand: "thermwell"
price: "$40.93"
currency: USD
in_stock: true
reviews_count: 8
category: "Thermwell"
url: https://www.desertcart.us/products/16882158-frost-king-ac43h-air-conditioner-weatherseal-tape-2-1-4
store_origin: US
region: United States of America
---

# 42-inch length for full window coverage Open cell foam for compressible, snug fit Resilient foam seals out air, insects & dust Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch

**Brand:** thermwell
**Price:** $40.93
**Availability:** ✅ In Stock

## Summary

> 🛠️ Seal smart, stay cool — don’t let your AC’s gaps ghost you!

## Quick Answers

- **What is this?** Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch by thermwell
- **How much does it cost?** $40.93 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/16882158-frost-king-ac43h-air-conditioner-weatherseal-tape-2-1-4)

## Best For

- thermwell enthusiasts

## Why This Product

- Trusted thermwell brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Easy Upgrade:** Simple peel-and-stick application for instant weatherproofing
- • **Durable Defense:** Resilient material withstands weather wear and tear
- • **Seal Like a Pro:** Compressible foam ensures airtight, insect-proof window AC installation
- • **Clean & Efficient:** Blocks drafts and dust to boost your AC’s energy efficiency
- • **Perfect Fit Every Time:** 42-inch length covers standard window AC gaps seamlessly

## Overview

THERMWELL Frost King AC43H Weatherseal Tape is a 42-inch open cell foam strip designed specifically for window air conditioners. Its compressible, resilient material effectively seals out air, insects, and dust, enhancing energy efficiency and comfort. Easy to install and durable, it’s a must-have upgrade for any millennial professional’s smart home toolkit.

## Description

Product Description 2-1/4" x 2-1/4" x 42", Dark Gray, Open Cell Foam Tape, For Weather-Stripping Around Window Air Conditioners, A Resilient, Compressible Strip For Sealing Out Air, Insects & Dust.Do not use it on paint or wallpaper. Manufacturer Contact Information 1-800-526-5265

Review: A Solid Weatherseal Upgrade for Window Air Conditioners - The THERMWELL Frost King AC43H Air Conditioner Weatherseal Tape is a simple but highly effective solution for sealing window AC units and eliminating the drafts, vibration noise, and dust gaps that tend to show up around older installations. The foam is dense enough to provide a firm, reliable seal, yet still compresses easily to fit uneven gaps without tearing or crumbling. At 2‑1/4 by 2‑1/4 inches and 42 inches long, the size is generous and works well for both side and top gaps on standard window units. During installation, the adhesive held securely without needing reinforcement, and once in place, the foam stayed put even through temperature swings and daily AC vibration. The material also rebounds well, maintaining its shape rather than flattening out over time. For anyone installing a new unit or tightening up an existing one, this weatherseal tape offers dependable performance, easy handling, and a noticeable improvement in insulation and noise reduction.
Review: Good stuff - It is what it is-‘firm but not too firm. Good for filling in a gap.

## Features

- For Weather-Stripping Around Window Air Conditioners
- Resilient, Compressible Strip For Sealing Out Air, Insects & Dust
- Open Cell Foam Tape

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0000DH4JL |
| Best Sellers Rank | #8,237 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #56 in Weather Stripping |
| Brand | Thermwell |
| Brand Name | Thermwell |
| Color | Gray |
| Customer Reviews | 4.7 out of 5 stars 3,493 Reviews |
| Global Trade Identification Number | 00077578030401 |
| Included Components | Foam Insulation |
| Item Dimensions L x W | 42"L x 2.25"W |
| Item Thickness | 2.25 inches |
| Item Type Name | Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch |
| Item Weight | 0.27 g |
| Manufacturer | Thermwell Products Co., Inc |
| Manufacturer Contact Information | 1-800-526-5265 |
| Manufacturer Part Number | AC43H |
| Manufacturer Warranty Description | Manufacturer's warranty against defects. |
| Material | Foam |
| Material Type | Foam |
| Model Number | AC43H |
| Number of Items | 1 |
| Number of Packs | 1 |
| Product Dimensions | 42"L x 2.25"W |
| Recommended Uses For Product | Window |
| UPC | 077578030401 |
| Unit Count | 3.5 Feet |

## Product Details

- **Brand:** Thermwell
- **Color:** Gray
- **Item Thickness:** 2.25 inches
- **Material:** Foam
- **Product Dimensions:** 42"L x 2.25"W

## Images

![Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch - Image 1](https://m.media-amazon.com/images/I/5169stJ7b+L.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: can the weatherseal go between the bottom of the air conditioner and the window sill?)**
A: If there is space then yes. It’s a foam so you can manipulate it into the smallest crevices.

**Q: does it absorb moisture?**
A: Never had to experience moisture

**Q: What is the maximum temperature rating of this foam?**
A: Sorry, no idea. I use it for insulation. It does not come with temperature ratings listed,  but as it's very light, thick sponge rubber I wouldn't think it would withstand very high heat.

**Q: Is it washable?**
A: It can be hand-washed in mild soapy water' rinsed and air-dried as long as the foam has not gotten crumbly with age.

## Customer Reviews

### ⭐⭐⭐⭐⭐ A Solid Weatherseal Upgrade for Window Air Conditioners
*by M***8 on January 3, 2026*

The THERMWELL Frost King AC43H Air Conditioner Weatherseal Tape is a simple but highly effective solution for sealing window AC units and eliminating the drafts, vibration noise, and dust gaps that tend to show up around older installations. The foam is dense enough to provide a firm, reliable seal, yet still compresses easily to fit uneven gaps without tearing or crumbling. At 2‑1/4 by 2‑1/4 inches and 42 inches long, the size is generous and works well for both side and top gaps on standard window units. During installation, the adhesive held securely without needing reinforcement, and once in place, the foam stayed put even through temperature swings and daily AC vibration. The material also rebounds well, maintaining its shape rather than flattening out over time. For anyone installing a new unit or tightening up an existing one, this weatherseal tape offers dependable performance, easy handling, and a noticeable improvement in insulation and noise reduction.

### ⭐⭐⭐⭐⭐ Good stuff
*by J***O on July 25, 2026*

It is what it is-‘firm but not too firm. Good for filling in a gap.

### ⭐⭐⭐⭐⭐ Weather stripping
*by J***N on August 31, 2026*

Great item

## Frequently Bought Together

- THERMWELL Frost King AC43H Air Conditioner Weatherseal Tape, 2-1/4 by 2-1/4 by 42-Inch
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---

*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-09-25*