Opteka EF-710 DG Super TTL Autofocus Dedicated Flash for Pentax K-30, 645D, Q, K-5, K-r, K-x, K-7 and Samsung NX10, NX100 Digital SLR Cameras Works on all Pentax and Samsung Digital SLR Cameras Bounce capabilities in 5 steps up to 90 degrees; flash shooting distance range from 2 and up to 72 feet 35mm angle of coverage with Pentax and Samsung digital SLR cameras Operates on two AA batteries; fast 0.3-10 second recycling time Guide number (ISO100) 22(m)/72(ft) at 35mm