The filter thread size of Nikon AF-S DX Nikkor 18-200mm f3.5-5.6G ED VR II is 72mm.
Below are links to the filters that we recommend you to consider for your Nikon 18-200mm f3.5-5.6G ED VR II:
Read our detailed Nikon AF-S DX Nikkor 18-200mm f3.5-5.6G ED VR II Review