This wig has monofilament. This can either be in the form of a lace front, 100% hand-tied top, a 100% hand-tied cap, or a combination thereof. This is a technique that requires many hours of labor. This makes these wigs wearable works of fashion art and the price tends to reflect it.
Results will vary. No two people thread wigs in the exact same way and each wig should be expected to be slightly different due to this human artistry. Results will vary between wig to wig, even in two wigs of the exact same style and color from a single brand.
They fit close to the head and do not stretch (much). Monofilament features are meant to fit very close to the scalp as a sort of second skin, so they are designed to have a very snug fit. Monofilament mesh lace is a relatively stiff material and does not stretch as much as comparable quality elasticized open caps.