Wingspan 18-20 mm.
This moth flies at dusk and at night from late June, into July. By day it rests in trees and tall bushes in Oak woodland. It has a distinctive broad reddish area in the middle of the forewing.
Distributed rather locally through England and Wales, it also occurs in Ireland. The larvae feed on a range of trees, including oak (Quercus) and alder (Alnus), usually within a folded leaf.