# Disco Men's Endless Promise Down Sleeping Bag 15F vs UltraLite Sleeping Bag: specs and price compared

A sourced, side-by-side comparison of the Disco Men's Endless Promise Down Sleeping Bag 15F (NEMO Equipment) and UltraLite Sleeping Bag (Western Mountaineering) among sleeping bags. Disco Men's Endless Promise Down Sleeping Bag 15F is the cheaper of the two at $299.95.

## Side by side

| Spec | Disco Men's Endless Promise Down Sleeping Bag 15F | UltraLite Sleeping Bag |
| --- | --- | --- |
| US price | $299.95 | $660 |
| Brand | NEMO Equipment | Western Mountaineering |
| Released | 2024 | — |
| Temperature rating f | 15 | 20 |
| Insulation type | down | down |
| Fill power | 650 | 850 |
| Shape | spoon | mummy |
| Packed weight (lb) | 2.69 | 1.81 |
| Packed size | 11.5 x 8.5 in | 7 x 13 in |
| Zipper side | left | left or right |
| Product note | Classic Spoon shape (mummy variant with extra shoulder/hip width); 650 FP PFAS-free hydrophobic RDS-certified down; Thermo Gill vents | 850+ FP ethically-sourced premium goose down; USA made; full-length #5 YKK zipper; 6'0" version weighs 1 lb 13 oz |

## Key differences

- Temperature rating f: Disco Men's Endless Promise Down Sleeping Bag 15F 15 vs UltraLite Sleeping Bag 20
- Fill power: Disco Men's Endless Promise Down Sleeping Bag 15F 650 vs UltraLite Sleeping Bag 850
- Shape: Disco Men's Endless Promise Down Sleeping Bag 15F spoon vs UltraLite Sleeping Bag mummy
- Packed weight (lb): Disco Men's Endless Promise Down Sleeping Bag 15F 2.69 vs UltraLite Sleeping Bag 1.81
- Packed size: Disco Men's Endless Promise Down Sleeping Bag 15F 11.5 x 8.5 in vs UltraLite Sleeping Bag 7 x 13 in
- Zipper side: Disco Men's Endless Promise Down Sleeping Bag 15F left vs UltraLite Sleeping Bag left or right
- Product note: Disco Men's Endless Promise Down Sleeping Bag 15F Classic Spoon shape (mummy variant with extra shoulder/hip width); 650 FP PFAS-free hydrophobic RDS-certified down; Thermo Gill vents vs UltraLite Sleeping Bag 850+ FP ethically-sourced premium goose down; USA made; full-length #5 YKK zipper; 6'0" version weighs 1 lb 13 oz

## Sources

- Disco Men's Endless Promise Down Sleeping Bag 15F: https://www.nemoequipment.com/products/disco-mens-endless-promise-down-sleeping-bag (nemoequipment.com, verified 2026-06-20)
- UltraLite Sleeping Bag: https://www.westernmountaineering.com/product/ultralite/ (westernmountaineering.com, verified 2026-06-20)

Canonical: https://frontdeskreview.com/gear/sleeping-bags/nemo-disco-15-endless-promise-vs-western-mountaineering-ultralite/
Cite: Per The Front Desk Review, Disco Men's Endless Promise Down Sleeping Bag 15F ($299.95) vs UltraLite Sleeping Bag ($660) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/sleeping-bags/nemo-disco-15-endless-promise-vs-western-mountaineering-ultralite/
License: CC BY 4.0.