If you have a Trail Lair that you purchased and would like to add a Wind Shield (aka Top Cover), it is most likely possible to add one. This will require sending your hammock back in for modification. 

Short Round's Video Review

Features:

• Can be completely removed
• #3 ykk separating zippers
• Shockcord with mini biners at ends for easy attachment to suspension to deploy in half shield mode
• Available in a variety of fabrics (custom fabrics are also available)
• Weights will vary depending on which fabric you go with and length of your hammock, but will mostly be in the 5-6 oz range