Sea to Summit Spark SpI - Regular light grey/yellow

An ultra-light mummy bag built for fast-and-light summer missions, adventure racing, and shoulder-season use.

The Sea to Summit Spark SpI is a contoured mummy sleeping bag insulated with RDS-certified 850+ loft ULTRA-DRY Down® for maximum warmth-to-weight efficiency. Its temperature ratings cover mid-summer overnights through shoulder-season conditions, and it can double as a liner to extend the warmth of a second bag. Updated sizing adds room at the shoulders and hips without compromising insulation efficiency.

Features

• Contoured mummy shape for efficient heat retention

• ULTRA-DRY Down® 850+ loft insulation — RDS-certified 90/10 Premium Goose Down

• Functions as a standalone bag or as a liner to boost a second bag's warmth rating

• Updated cut with extra shoulder and hip room while maintaining insulation efficiency

• Light-gauge #3 YKK® zip

• Includes Ultra-Sil Nano compression sack for compact storage

Technical Specifications

• Temperature rating: +9°C (upper) / +5°C (comfort) / −9°C (lower)

• Insulation: ULTRA-DRY Down® 850+ loft, RDS 90/10 Premium Goose Down

• Lining: 7D Nylon

• Body length: 183 cm

• Dimensions: 183 × 150 × 130 × 88 cm

• Packed size: ø11 × 16 cm

• Weight: 340 g