templet not correct and screw heads too large.
Templet for the bulbs was correct as were the top holes but the bottom holes were an inch off. Note, do not remove the back cover sheet and expose the sticky back. You will have a lot of trouble getting the templet off. Instead tape the templet  to the duct. Also get some real sheet metal screws say #6 x 1/2". Measure the head of the screw and get a drill bit the same size and drill open the key slots on the unit so the screw head will go thru. Cut out the two large bulb holes on the duct first making sure they match location with the actual bulb sockets before you cut. Put unit without bulbs on the duct making sure you are centered and mark the top of the key slots. My top slots were very close to the templet. Remove unit and drill the top two screw holes and put screws in and hang the unit making sure you slide to the end of the screw slots. Now mark the top of the bottom screw slots, remove unit, drill bottom holes and put in screws. Rehang unit to make sure all screw holes fit. Remove unit and install bulbs making sure they are tight. DO NOT TOUCH THE GLASS ON THE BULBS, if you do get some alcohol and clean the glass. Carefully insert the bulbs and unit into duct over the screws and slide down. Tighten screws snugly but not over tighten or you might strip the threads. Hope this helps.
Rating: 4 stars