The MT-26EX-RT Macro Twin Lite from Canon is a macro flash that uses a pair of flashes to evenly illuminate your subject when working with a macro lens. When both flash heads are simultaneously fired, they offer a guide number of 85.3 at ISO 100, and extensive manual adjustment allows you to dial in settings down to 1/512 power. Both flash heads are detachable and, using the 2.4 GHz wireless triggering system, the heads can be easily positioned around the subject for more controlled dynamic lighting configurations, including the ability to easily integrate other flashes into the system. When attached to the lens, the heads can be rotated up to 60° horizontally and 45° vertically and both include a removable diffuser for further adjustment over light output. An illuminated dot-matrix LCD screen lets you make adjustments to the flash in both bright and low-light situations, and its updated white LED focus assist lamps aid in achieving accurate focus. The recycling time with 4 AA batteries is from 0.1-5.5 seconds. The MT-26EX-RT is compatible with the following lenses: EF 50mm f/2.5 Compact Macro EF-S 60mm f/2.8 Macro USM EF 100mm f/2.8 Macro USM MP-E 65mm f/2.8 1-5x Macro Photo EF 100mm f/2.8L Macro IS USM with separate Macrolite Adapter 67 EF 180mm f/3.5L Macro USM with separate Macrolite Adapter 72C TS-E 50mm f/2.8L Macro TS-E 90mm f/2.8L Macro TS-E 135mm f/4L Macro