Flash Head , Guide Number 154.2' / 47 m at ISO 100 (105 mm Position), Coverage Full-Frame, Internal Power 4 x AA (Alkaline, NiMH), External Power Pack Compatible No, Mount Shoe, Off-Camera Terminal None, Dimensions (W x H x D) 2.9 x 5.1 x 4.1" / 73.7 x 129.5 x 104.1 mm, Weight 13.6 oz / 385.6 g