The Pentax AF-540FGZ is a premium clip-on-type auto-zoom flash unit designed for Pentax SLR and DSLR cameras. This powerful flash features a guide number of 54 (at ISO 100) and offers advanced flash capabilities including P-TTL auto flash, high-speed synchronisation, wireless P-TTL functionality, and multi-flash modes for creative stroboscopic photography. The flash head automatically adjusts its angle of discharge to match your lens focal length, with zoom coverage from 24mm to 85mm (plus a built-in wide-angle panel for 20mm). It provides versatile bounce and swivel functionality with tilt angles from -10 to +90 degrees and 180-degree horizontal rotation. Powered by four AA batteries, this flash is a compact yet powerful addition to your Pentax kit, ideal for both daylight sync photography and advanced lighting scenarios.