Wrapped sights have X number offeet of fiber optic, usually wrapped around the pin guard (although not always) My HHA has 10'. The longer fiber optics gather more light and therefore results in a brighter pin. My HHA has a pin guard that allows you to adjust the brightness by exposing as much or as little of the optics to light as you need to. You can then have just the right pin brightness for the conditions, in a blind, cloudy day, sunny day, etc., etc.

Dan