Hensel Integra Plus 500FM (Freemask) Short flash duration down to 1/1,400 s and fast flash sequences from 0.5 s Adjustable 6 f-stop power range in 1/10 f-stops; Bi-voltage (110 V and 230 V) Bright 300W model light & active cooling; Stable metal housing Built-in Strobe Wizard Plus radio receiver with freemask Freemask function - cut-out masks in perfect quality while shooting