This description sounds like it would make for a great jacket! A Thermolite-filled, lightweight jacket designed for warmth and comfort with a 550 Fill Power would indeed provide excellent insulation and protection against cold weather. Its packable nature makes it versatile and convenient for a range of activities, including commuting, hiking, and other outdoor adventures. The option to pack it into its own sac when it gets too warm is also a practical feature. It seems like a well-designed jacket for people who want to stay warm and comfortable without sacrificing mobility and convenience.

Features -

• Packable
• Thermolite fill 135g
• 550 fill power
• Water repellent outer (600 mm)
• YKK front zip
• Reflective detailing
• Elasticated cuffs
• Lightweight
• Scoop back hem
• PFC & PFOA free