Elloughton Greenhouses Bayliss Mk.7 Spare Cylinder Kit. Replacement Power Tube for Bayliss Mk.7 Autovents, (Excluding MK.7 Super Variants) Genuine Bayliss Mk.7 Replacement Cylinder Kit Power Tube, Star washer, Fitting Instructions Fits all Mk.7 Autovents Except Mk.7 Super All parts needed included in this kit Fite Mk.7, Mk.7 triple Spring and Mk.7 Hydraulicheck