This set contains a 22 MM - Pure Perfect Fit Silk Hair Cap and a 22 MM - Pure Long Silk Hair Bonnet. You can put your long hair in the nightcap very relaxedly, instead of being folded on the head like the short nightcap, it can be easily worn on the head before going to bed. Silk can effectively keep the hair properly hydrated, not frizzy, and is beneficial for the hair.