---
url: "https://onebag.travel/compare/5uozk4l5zy/ks-ultralight-ks27/cfo1f254gp/rei-co-op-trail-pack-25/"
title: "KS Ultralight KS27 vs REI Co-op Trail Pack 25"
description: "KS Ultralight KS27 vs REI Co-op Trail Pack 25: capacity, weight, dimensions and how many airlines accept each as a carry-on, side by side."
source: "https://onebag.travel/compare/5uozk4l5zy/ks-ultralight-ks27/cfo1f254gp/rei-co-op-trail-pack-25/"
---
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3.  KS Ultralight KS27 vs. REI Co-op Trail Pack 25

# KS Ultralight KS27 vs. REI Co-op Trail Pack 25

Two carry-on travel backpacks, compared spec for spec.

## [KS Ultralight KS27](https://onebag.travel/carryon/5uozk4l5zy/ks-ultralight-ks27/)

by [KS Ultralight](https://onebag.travel/carryons/?brands=KS Ultralight)

![Front facing view of the KS Ultralight KS27](https://res.cloudinary.com/obt/image/upload/c_fill,w_400/v1788990375/carryons/ks-ultralight-ks27-5uozk4l5zy.webp)

<table class="table table-sm cmp-spec mt-2"><tbody><tr><td>Capacity</td><td>27 L</td></tr><tr><td>Weight</td><td>0.3 kg</td></tr><tr><td>Dimensions</td><td>55×28×16 cm</td></tr><tr><td>Airline fit</td><td>87%</td></tr><tr><td>Price</td><td>$130</td></tr></tbody></table>

## Feature by feature

| KS Ultralight KS27 | Feature | REI Co-op Trail Pack 25 |
| --- | --- | --- |
| Storage |
| 2 | Compression | 2 |
| None | Expanded Capacity | None |
| 0 | Opening | 0 |
| top | Passport | top |
| N | Passthrough | N |
| Carry |
| Y | Backpack | Y |
| removable | Hip Belt | removable |
| removable | Sternum Strap | Y |
| Inside |
| N | Laptop | N |
| 2 | Main Compartments | 3 |
| N | Organizer | N |
| Outside |
| × | Hard Shell | × |
| N | Rain-fly | Y |
| 2, side | Water Bottle Holder | 2, side |
| Y | Water Resistant | Y |

<table class="cmp-material"><tbody><tr><td colspan="2">Material</td></tr><tr><td>X-pac VX 07 YKK "waterproof zip"</td><td>210-denier ripstop nylon</td></tr></tbody></table>

## [REI Co-op Trail Pack 25](https://onebag.travel/carryon/cfo1f254gp/rei-co-op-trail-pack-25/)

by [REI Co-op](https://onebag.travel/carryons/?brands=REI Co-op)

![Front facing view of the REI Co-op Trail Pack 25](https://res.cloudinary.com/obt/image/upload/c_fill,w_400/v1601602563/carryons/reicoop_o83w5i.webp)

<table class="table table-sm cmp-spec mt-2"><tbody><tr><td>Capacity</td><td>25 L</td></tr><tr><td>Weight</td><td>0.8 kg</td></tr><tr><td>Dimensions</td><td>46×33×20 cm</td></tr><tr><td>Airline fit</td><td>94%</td></tr><tr><td>Price</td><td>$100</td></tr></tbody></table>

## Key differences between the KS Ultralight KS27 and REI Co-op Trail Pack 25

-   **Sternum strap:** Removable on the KS Ultralight KS27; Yes on the REI Co-op Trail Pack 25.
-   **Main compartments:** 2 on the KS Ultralight KS27; 3 on the REI Co-op Trail Pack 25.
-   **Rain cover:** No on the KS Ultralight KS27; Yes on the REI Co-op Trail Pack 25.

Both have: compression straps, passport pocket, backpack straps, hip belt, water bottle pockets, water resistant.

## Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 163 accept both. 1 accept only the KS Ultralight KS27, and 14 accept only the REI Co-op Trail Pack 25.

### Only the KS Ultralight KS27 fits

Great Lakes Airlines.

### Only the REI Co-op Trail Pack 25 fits

American Eagle, Belavia, easyJet, Etihad Airways, Liat Airlines, Oman Air, Qatar Airways, Ravn Alaska, Regional Express, Royal Jordanian, Scoot, Tiger Airways, Virgin Australia, WestJet.

## KS Ultralight KS27 vs. REI Co-op Trail Pack 25: which should you pack?

The **KS Ultralight KS27** carries 2L more than the **REI Co-op Trail Pack 25** (27L vs. 25L), while the **KS Ultralight KS27** is the lighter pack at 0.3kg (vs. 0.8kg). For carry-on flexibility, the **REI Co-op Trail Pack 25** fits 94% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the KS Ultralight KS27; if you want to travel lighter, the KS Ultralight KS27 is the better call.