This is the last iteration of the glorious Zenitar 16mm. I’m guessing this brand new shiny version came out in 2012, but please if you have any solid info correct me.
Filters are rear screw-in, M26,5х0,5, usually delivered with the lens there is a clear filter, screwed on, a yellow-green, a light yellow, and a red one.
The new lens was improved in many ways, reading the manufacturer’s website. I got mine and I’m waiting to test it, I can already say the overall feeling changed a lot. All rubber and plastic are gone, materials are changed as manufacturing dramatically improved. The appearance is more refined and the clumsy but solid mechanical feeling has changed in a smooth, precise, high-quality statement.
The lens is available from the manufacturer’s website as well as many online sellers.