Silnylon base layer with bathtub construction. Pertex top. Mesh netting. Two way double zip runs across mesh and 2 feet down side. Room inside for mat and down bag. Actually my winter bag fits in no bother.
Weight is 350g with mesh stuff sack.
Lessons learned:
1. sizing is generous. Could trim weight by making smaller.
2. Could use lighter top material.
3. Zip was from an old tent. Could use smaller and lighter zip