3 1/2" Vertical Blind Replacement Slat (Crown Alabaster)

Purchased 50 slats to redo a Hunter Douglas frame. Old ones had yellowed badly from the sun in Florida. I received the correct color (Alabaster) and quantity and replaced the old ones. The new ones are more or less translucent and let a LOT of light to enter the bedroom. I expected enough heft in the product to block most of the light, but I didn't specify room darkening. This may have been my error, but I expected the new slats to stop most of the light. They clearly don't do that.