Jinbei HD600 II HSS Mobile Battery Hand Studio Strobe Is Now Upgraded to HD600V New Arrival Upgraded Jinbei HD II-600 Mobile Battery Studio Strobe Flash. adopts the most advanced driving circuit design. Better performance, more stable and more reliable You can mount it on a light stand like a conventional studio light or have an assistant hand-hold it, that can be used Indoor and Outdoor Please be aware to use that the High Speed Sync / HSS function the HSS flash trigger such as the YN-622 or Pixelking required! The HSS mode by simultaneously pressing the Set and eye icon button activates the device (photocells function / Multi mode). The control range for High Speed Sync mode is 1/1 to 1/16