Can I use this with 9 40 watt LED bulbs?

Hello Marina, thank you for your question. The Diva LED+ Dimmer is rated for up to 150 watts of LEDs or up to 600 watts of incandescent/halogen lighting. If the LED bulbs say "40 watts," it is likely that that is a wattage equivalent; in other words, equivalent to 40 watts of light output, but due to the low power draw of LEDs, likely uses much less power than that per bulb. We recommend finding the actual used wattage of each bulb, multiplying that by the nine bulbs in the application, and as long as this is below the device's 150 watt limit, it will be suitable for this device. See the below spec sheet for more information: https://assets.lutron.com/a/documents/369682.pdf We hope this helps! If you require further assistance, our 24/7 support team is here to help. We can be reached at 1-844-LUTRON1 or via email at support@lutron.com.