# Sidewinder SL 20 Mummy Sleeping Bag: specs and price

**Price (US):** $199.96 at bigagnes.com, as of 2026-07-26. A sourced, dated price of record — other retailers (incl. Amazon) may be lower. Among the 17 sleeping bags we track it is #8 cheapest of 17; category median $200.
**Brand:** Big Agnes
**Deskmark:** Bronze Deskmark — pay-blind category standing 57/100, #8 of 13 in class (independent, computed from sourced data, never for sale).
**Price tracked since:** June 2026 (last change 2026-07-26: $249.95 → $199.96)

## Specifications

| Spec | Value |
| --- | --- |
| Price (US) | $199.96 |
| Brand | Big Agnes |
| Temperature rating f | 20 |
| Insulation type | down |
| Fill power | 650 |
| Shape | mummy |
| Packed weight (lb) | 2.25 |
| Packed size | 6.5 x 8 in |
| Zipper side | center |
| Product note | 650-fill DownTek hydrophobic down with body-mapped FireLine ECO synthetic at pressure points; designed for side sleepers; center ambidextrous zipper |

## Where it stands

At $200, the Sidewinder SL 20 Mummy Sleeping Bag is #9 cheapest of the 17 sleeping bags we track, where the median is $249.95. On the spec sheet, its fill power of 650 is below the median of the 11, its packed weight of 2.25 lb is below the median of the 13, and its temperature rating f of 20 is at the median of the 19.

## Price over time

Since 2026-06-27, the Sidewinder SL 20 Mummy Sleeping Bag's price has fallen 20%, from $249.95 to $199.96. At $199.96 it is the lowest we have recorded.

## Frequently asked questions

**How much does the Sidewinder SL 20 Mummy Sleeping Bag cost?**

The Sidewinder SL 20 Mummy Sleeping Bag has a US price of $199.96, as of 2026-07-26.

**How does the Sidewinder SL 20 Mummy Sleeping Bag compare on price?**

At $200, the Sidewinder SL 20 Mummy Sleeping Bag is #9 cheapest of the 17 sleeping bags we track, where the median is $249.95.

**Has the Sidewinder SL 20 Mummy Sleeping Bag's price dropped?**

Yes — since 2026-06-27 the Sidewinder SL 20 Mummy Sleeping Bag has fallen 20%, from $249.95 to $199.96.

**What is the lowest price the Sidewinder SL 20 Mummy Sleeping Bag has been?**

The lowest we have recorded for the Sidewinder SL 20 Mummy Sleeping Bag is $199.96 on 2026-07-26 — which is its current price.

**Is now a good time to buy the Sidewinder SL 20 Mummy Sleeping Bag?**

At $199.96, the Sidewinder SL 20 Mummy Sleeping Bag is at the lowest price we have recorded since 2026-06-27.

**What are the Sidewinder SL 20 Mummy Sleeping Bag's key specs?**

Sidewinder SL 20 Mummy Sleeping Bag (Big Agnes): temperature rating f 20, insulation type down, fill power 650, shape mummy, packed weight lb 2.25. Full sourced spec sheet verified 2026-06-20.

Source: https://www.bigagnes.com/products/sidewinder-sl-20 (bigagnes.com, accessed 2026-06-20)
Corroboration: https://www.campman.com/blog/gear-review-big-agnes-sidewinder-sl-20-sleeping-bag/ (accessed 2026-06-20)
Canonical: https://frontdeskreview.com/product/sleeping-bags/big-agnes-sidewinder-sl-20/
Cite: Per The Front Desk Review, the Sidewinder SL 20 Mummy Sleeping Bag price of record was $199.96 as of 2026-07-26 — https://frontdeskreview.com/product/sleeping-bags/big-agnes-sidewinder-sl-20/
License: CC BY 4.0. Price history: https://frontdeskreview.com/data/price-history.jsonl