Series 1 Power box assembly with built-in air flow switch and W8600F compatibility. This power box has an overall size of 12.5 x 6.5 x 3 inches. Includes a 60 inch power cord with 3-prong plug. Honeywell 2 year warranty. Installation is simple, mounts with two screws, then plug in. This Series 1 power box is equipped with a terminal strip for the W8600E. If using this power box without a W8600E or W8600F, then Series 1 or 2 does not matter. When using this power box with the newer W8600F, then replace the terminal strip and driver card with that supplied with the W8600F. Used in the 12.5x20 F50F1040 120v. Replaces 203316A.