Ricoh Imaging announces a new Penatx AF180FG compact auto flash, compatible with both Pentax DSLRs and Ricoh GR cameras (check of pre-orders at Adorama, Amazon, and B&H Photo): Supports P-TTL Up to 135° bounce flash Weather-resistant Additional information:
The Pentax AF540FGZ II flash is now listed as discontinued in Japan. In the US the flash unit is still in stock at Adorama and B&H Photo. More discontinued Pentax products can be found here.
Godox confirmed to me that the new Godox Lux Senior Retro camera flash is compatible with Pentax cameras: Pre-order here Product page Technical specification, related video, and additional pictures: