This popular Thyristor circuitry-portable flash unit provides long battery life and fast recycle times along with your choice of four auto f/stop settings. The 285HV features an extended automatic range to 70' with a three-position, tilting zoom head.Features:Guide number 120 (ISO 100') at 50mm4 auto f/stop settingsAuto thyristor circuitryVertical bounce flashZoom flash headVariable power control with optional VP-1Remote sensor capabilitySufficient light indicatorIlluminated calculator dialPower source: 4 AA batteries, NC-3 NiCad Battery or SB-4110V AC adapter