Wingspan 22-25 mm.
The larvae of the Psychidae are quite unusual in that they live their entire lives in a larval 'case' built from debris.
The adult male is a dull brownish-grey moth, but the female is apterous, or wingless, and has much reduced legs, looking rather like a yellowish grub.
This is a rare and threatened species in Britain, occurring only on heathland in Dorset and Hampshire.
The males fly in the sunshine during June and July.