Probable peripherally associated component of the endosomal sorting required for transport complex III (ESCRT-III) which is involved in multivesicular bodies (MVBs) formation and sorting of endosomal cargo proteins into MVBs. Interacts with SKD1/VPS4 AND LIP5 (PubMed:20663085). Interacts with VPS2.2 (PubMed:22010978). Localized in multivesicular body when associated with SKD1. Additional isoforms seem to exist. Belongs to the SNF7 family.