Tiffen soft edge horizontal graduated ND filter set with 0.3, 0.6 and 0.9 grad filters. PV / 4x5.65" size.
Use graduated ND filters to balance exposure within a scene - typically to balance the sky with the foreground - or for other creative applications.
Soft edge grads are most often used with wide to standard angle lenses. For longer lenses, hard grads are often preferred.