The filter thread size of Fujifilm XF 18-135mm F3.5-5.6 R LM OIS WR is 67mm.
Below are links to the filters that we recommend you to consider for your Fujifilm 18-135mm F3.5-5.6 R OIS:
Read our detailed Fujifilm XF 18-135mm F3.5-5.6 R LM OIS WR Review