The Godox V1-P (Pentax) AK-R1 Accessory Head Kit includes both the new Godox V1 and the Godox AK-R1. 

Godox V1-P Round Head Flash for Pentax

Offering a powerful 76Ws output along with a distinct design, the Godox V1 Flash is an advanced light source with features that clearly reflect the current state of the industry. Compatible with Pentax P-TTL, this flexible on-camera light is distinguished by its round head, which provides soft, smooth light with gradual fall off that augments the flattering output. The head rotates 330 degrees, tilts -7 to 120°, and has a magnetic surface for lightning-fast attachment of Godox's accessory light modifiers.

The V1 is powered by a removable 2600mAh lithium-ion battery that will give you up to 480 full-power flashes on a charge, so you don't miss any of the action. Speaking of speed, the V1 recycles to full power in just 1.5 seconds, fast enough to keep up with your subject. It also supports High Speed Sync up to 1/8000 sec, for managing bright backgrounds and shooting with wide apertures, and the V1 supports front and rear-curtain sync.

The V1 has an optical slave but it's also got a built-in 2.4 GHz receiver, which accepts wireless signals from Godox X System transmitters. In fact, you can control up to four wireless groups in a master/slave configuration whereby settings made on the V1 are duplicated on the slave flashes. Other convenience features include an AF assist lamp, a 3200K LED modelling lamp, and a 2.5mm port for cabled triggering.