I bought this bag for the Highland Trail. Unfortunately broken bones put paid to that for a year, but the bag has still got plenty of use over the spring and summer.

Specs, copied and pasted from the Rab website:

The Neutrino Endurance series are a range of down filled sleeping bags that replaced the Alpine range of sleeping bags, like their namesake jacket these bags are ideal for use in Alpine conditions.

The Neutrino Endurance series of bags are a range of down filled bags using 800 fill power European Goose down that are designed primarily for use by Alpine climbers. The outer fabrc is Pertex Endurance that is water resistant and offers piece of mind and protection in damp environments. The bag is a mummy taper shape so is streamlined and tapered to offer minimum weight and maximum warmth. The bag uses a lightweight Pertex Quantum lining that allows the down fill to loft to its maximum. The Neutrino Endurance bags are ideal for use on Alpine bivi ledges, for lightweight backpacking in inclement weather or for year round use in tents to offer protection and piece of mind from spillages and condensation.

Comfort 5°C

Limit of Comfort 0°C

Extreme -16°C

Weight: 685gg / 24.2oz (+60g / 2.1oz stuffsac)

• Pertex® Endurance outer fabric
• Pertex Quantum® inner fabric
• Pertex® Endurance inner fabric in hood and collar
• 800FP European Goose Down
• Mummy taper shape
• Proportionally assigned differential cut
• Internal YKK 3 coil zipped stash pocket
• 3⁄4 length YKK 5 coil main zip on 400 and 600
• 1⁄2 Length YKK 5 coil main zip on 200
• Left and right hand zips available (Women’s Neutrino 600 left zip only)
• Extra long (additional 15cm) available on 400 and 600 (left zips only)
• Anti snag zipper webbing tape
• Internal collar and hood drawcord • Trapezoidal baffle chamber design • Angled foot box
• Dry bag compression stuff sack
• Cotton storage sack
• Hand filled in Derbyshire UK