Pentax 18 135mm f 3 5 5 6 vs pentax 16 85mm f 3 5 5 6?

Here is what the site says about that.

From [Pentax smc DA 18-135mm f/3.5-5.6 ED AL [IF] DC WR: Pentax smc DA 18-135mm f/3.5-5.6 ED AL [IF] DC WR](/gear/lenses/pentax-smc-da-18-135mm-f-3-5-5-6-ed-al-if-dc-wr/): A zoom lens by Pentax for APS-C cameras, 18-135mm f/3.5-5.6.

From Pentax HD DA 16-85mm f/3.5-5.6 ED DC WR: Pentax HD DA 16-85mm f/3.5-5.6 ED DC WR: A zoom lens by Pentax for APS-C cameras, 16-85mm f/3.5-5.6.

Quoted from this site's pages.