Lucid 4 Inch Gel Memory Foam Mattress Topper Twin XL
- Size: Twin XL
- Item Firmness Description: Soft
- Material Type: Memory Foam
- Water Resistance Level: Not Water Resistant
Last refreshed Sep 7, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
Twin XL sleepers wanting a deep, plush, cooling layer get CertiPUR-US certification and a 3-year warranty backing this 4-inch foam topper.
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ASIN: B01MYVATSJModel: LU40TX30GTCategory: Mattress Toppers
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Overview
Four inches of cooling gel memory foam make up this Lucid topper, cut with ventilation channels and sized for a twin XL mattress, often a dorm-room fit. CertiPUR-US certification and a 3-year limited warranty back the foam itself.
Lucid sells this same line in 2, 3 and 4 inch profiles; the 4-inch version here is the deepest, most sink-in option, while the thinner profiles are the pick for a firmer add-on. Like most compressed foam, it ships rolled in a box and needs 24 to 48 hours to fully decompress before the feel can be judged.
- Twin XL size, 4-inch profile
- Cooling gel infused memory foam
- CertiPUR-US certified
- 3-year limited warranty
Who it's for
Dorm rooms and twin XL beds wanting a noticeably plusher, cooler layer are the target for this 4-inch profile. Buyers wanting a thin, firm topper should look at Lucid's 2 or 3 inch versions instead.
Pros and cons
- Cooling gel plus ventilation channels against heat retention
- CertiPUR-US certified foam
- 3-year limited warranty
- Needs 24 to 48 hours to decompress
- Deep, plush profile, not for firmer support
Performance notes
Cooling gel infused through the foam and precision-cut ventilation channels work against heat retention, the main complaint against plain memory foam. Because it ships compressed, expect it to look thinner than 4 inches on arrival, with the brand quoting 24 to 48 hours before it reaches full loft. CertiPUR-US certification covers the foam's chemical content, and the 3-year warranty covers defects rather than normal softening.
Specifications
| Brand | Lucid |
|---|---|
| Model | LU40TX30GT |
| Dimensions & fit | |
| Size | Twin XL |
| Capacity & performance | |
| Age Range Description | Adult |
| Construction & materials | |
| Material Type | Memory Foam |
| Color | Blue Gel |
| Fabric Type | Memory Foam |
| Included components | |
| Number of Packs | 1 |
| Unit Count | 1 |
| Included Components | Mattress Topper |
| Warranty & support | |
| Manufacturer Warranty Description | 3 years |
| Other details | |
| Item Firmness Description | Soft |
| Water Resistance Level | Not Water Resistant |
| Closure Type | Pull On |
| Thread count | 400 |
| Number of Items | 1 |
| Product Care Instructions | Spot Clean Only |
| Other Special Features of the Product | Gel Memory Foam |
Closest rivals on specs
Sleepyhead 2 Inch Gel Memory Foam Mattress Topper Twin XL- Thread count 400 vs 320 (+25%)
Frequently asked questions
How long does the Lucid 4 inch topper take to decompress?
The brand states 24 to 48 hours after unrolling it from its shipping box before it reaches full thickness.
Is the Lucid memory foam topper certified?
Yes, it is assembled with CertiPUR-US certified foam and comes with a 3-year limited warranty.
Does the Lucid topper come in other thicknesses besides 4 inches?
The line is sold in 2, 3 and 4 inch profiles; this listing is the 4-inch, deepest and plushest option.