Comments about Okidata OKI� 43459303 High-Yield Toner Cartridge for C3400; Cyan:
Had to call service as toner was not responding when installed. I was told to check the shutter below the two copper things on the right side of the cartridge and if I didn't see a green spot I was to insert the tip of a paper clip to raise it. This solved my problem. It was inconvenient and time consuming to have to have to call service for a defective toner although it was fixable.
Bottom Line Yes, I would recommend this to a friend