Enhanced Warmth for Cooler Three-Season Adventures

The Robens Spire II -4°C Sleeping Bag is designed for campers, backpackers, and trekkers who need extra warmth when temperatures begin to drop. Featuring Robens' OneThermo® synthetic insulation, a heat-efficient body-contoured shape, and a range of cold-weather features, the Spire II delivers reliable performance across spring, autumn, and mild winter conditions.

A 3D hood, redesigned neck baffle, and insulated zip baffle work together to minimise heat loss, while the innovative shark fin foot box provides additional insulation where it's needed most.

Why You'll Love It

Increased Warmth for Colder Nights
→ Limit rating of -4°C for cooler conditions

Excellent Warmth-to-Weight Ratio
→ Body-contoured mummy design maximises thermal efficiency

Performs When Damp
→ Synthetic insulation continues to insulate in humid and wet conditions

Comfort-Focused Design
→ Soft brushed lining improves comfort and moisture management

Adventure Ready
→ Compression sack included for compact packing

OneThermo® Synthetic Insulation

The Spire II uses OneThermo® insulation, providing:

• Reliable warmth in cooler temperatures
• Good loft retention
• Fast drying performance
• Effective insulation in damp conditions
• Long-lasting durability for regular outdoor use

Ideal for UK camping, trekking, backpacking, and shoulder-season adventures.

Temperature Ratings

Comfort: 2°C
Limit: -4°C

Suitable for:

• Spring camping
• Autumn adventures
• Mountain camps
• Backpacking trips
• Cool-weather wild camping

Key Features

3D Hood Profile
→ Enhanced warmth around the head and neck

Redesigned Neck Baffle
→ Minimises heat loss and cold draughts

Differentiated Hood Drawcords
→ Easy adjustment in darkness

Shark Fin Foot Box
→ Additional insulation around the feet

Full-Length Insulated Zip Baffle
→ Prevents cold spots along the zip

YKK Auto Lock Two-Way Zip
→ Reliable operation and flexible ventilation

Anti-Snag Zip Guard
→ Smooth opening and closing

Brushed Polyester Lining
→ Soft-touch comfort with excellent moisture transport

Internal Pocket
→ Secure storage for valuables

Compression Stuff Sack Included

Hanging Loops for Drying & Storage

PFAS-Free Construction

Specifications

Weight: 1599g

Packed Size: 33 × 23 cm

Shell Fabric: 50D 300T Polyester Taffeta

Insulation: OneThermo®

Lining: 230T Microfibre Polyester

Zip: YKK Auto Lock Two-Way Zip

Materials:

• Shell: 100% Polyester
• Lining: 100% Polyester
• Filling: 100% Polyester

Perfect For

• Camping
• Backpacking
• Trekking
• Wild Camping
• Bikepacking
• DofE Expeditions
• Cool-Weather Adventures