The Lumedyne Accessory Tape Measure (Writable) can be used to record exposures and distances for different light modifiers (using the included marker to write on the 16' (4.8 m) tape measure). Simply use the tape measure when testing light modifiers, note the exposure(s) on the tape, and you can then set up on locaton without taking time-consuming light meter readings--just follow your notes on the tape while setting up the lights. A touch-tab strap on the tape measure's belt clip allows you to mount it to a lightstand. A quick way to accurately set lighting.