The BA Customer Service Policy Manual states that seat comfort devices are not approved for use on board, including but not limited to seat extenders (eg. JetKids BedBox), baby hammocks (eg. FlyeBaby), inflatable footrests, and devices that attach to the seat to restrict movement or provide leg support. (eg. FlyLegsUp, MonkeyGo, TravelSnug, FaceHammock, Knee Defender).