M42 Lens Adapter Ring Screw Mount Metal M42-EOS for Canon EOS M42-NIK for Nikon M42-PK for Pentax PK SLR Camera Lens Accessories - AliExpress Consumer Electronics
M42 / Pentax mount adapter guide | Vintage Camera Lenses
Kipon Adapter M42 to Pentax K | WALIMEX-WEBSHOP.COM - walimex-webshop.com
M42 Pentax universal screw Lens to PK KR K M Bayonet Camera mount adapter Ring | eBay
Amazon.com : Fotodiox Pro Lens Mount Adapter - M42 Screw Mount SLR Lens to Pentax K (PK) Mount SLR Camera Body : Electronics
Pentax Mount Adapter K (M42 Screwmount to K Mount) Reviews - Pentax K-mount Teleconverters and Adapters - Pentax Lens Reviews & Lens Database
How to adapt M42 Screw Mount lenses on a Pentax K mount Camera - YouTube