Buy Pentax D FA 15-30mm F2.8 HD ED SDM WR Autofocus Ultra Wide Angle Zoom Lens - National Camera Exchange
Pentax-M SMC 1:4 20mm ultra wide angle camera lens 4/20mm
Pentax HD DA Fisheye 10-17mm f/3.5-4.5 ED Lens 23130 B&H Photo
Laowa 12mm f2.8 Full Frame Super Ultra Wide Angle Lens for Sony E/A Canon RF/EF Nikon F/Z Pentax Leica Pentax Mount Camera - AliExpress
Amazon.com : Pentax D FA 21mmF2.4ED Limited DC WR Silver Ultra-Wide-Angle Single Focus Lens [for use with Full Frame DSLR ] Limited Lens, machined Aluminum Lens Barrel, (28050) : Electronics