Whispa III Kickspace Fan Convectors Radiators are engineered to simply last longer, stay quieter and deliver a heat output you can rely on for accuracy and reliability year after year. It fits easily under a counter, window seat or stairs. Myson Whispa III Kickspace 9000 fan-forced convector, output of 7634-9949 Btu/hr. Dimensions: 17-3/4″ x 12-1/8″ x 3-5/8″. Weight: 15 lbs. Fan speed (cfm): boost – 124, normal – 82. Cover grill is 4″ x 23-3/4″.