Ultralight compression to keep your pack spacious and light. When you need to compress your bulky gear without significantly adding weight, the Ultra-Sil Compression Sacks are the perfect choice. Made from high-strength 30D siliconised CORDURA fabric they can be compressed to one third of the original volume. Ideal for use inside your pack or travel bag when you need to compress clothing or bulky soft items to allow space for other essentials - or luxuries. The size range includes two extra small sizes good for compressing and storing down jackets and other clothing.Ultra-SilUltra-Sil is a very light nylon fabric. The outer shell is surrounded by a silicone layer; the inner layer is PU coated.