Traditional Culture Encyclopedia - Photography and portraiture - What is the meaning of WR Ⅱ marked on the thread diagram?

What is the meaning of WR Ⅱ marked on the thread diagram?

Was it taken by Pentax?

If it is a Pentax lens with WR logo, it means that the lens has been sealed and has certain waterproof performance. (Anti-drenching but not anti-foaming)

It is generally used with flagship fuselage with waterproof performance such as K-7 and K-5, which can support photographers to shoot in bad weather or environment.