FeaturesResilient anti-vibration motor mountsDynamically balanced polymeric centrifugal blower wheel for quiet, efficient performanceLow profile styling grille blends with any decorRugged 20 ga galvanized steel housing with 0.5 in acoustic insulation inside8-position mounting brackets for easy installation and greater adaptability to various mounting requirements, automatic backdraft damper located within duct connectorMay be installed as an in-line ventilator with addition of accessory kit model 982L, for controlling use model 57V (ivory)/57W (white) 3 A, electronic variable speed control or model 59V (ivory)/59W (white) 60 min time control or model 61V (ivory)/61W (white) 15 min time control or model 71V (ivory)/71W (white) 12 hr time controlPlug-in permanently lubricated thermally protected motor designed for continuous operationLow rpm for quiet operation blower434 cfm at 1/8 in SP horizontal, 2.3 Sones, 416 cfm at 0.1 in SP at 1/8 in SP vertical, 2.6 SonesRound ductSquare shape grille735 rpm horizontal, 755 rpm at 0.1 in SP vertical AC motor