The olympus stf 8 macro flashgun features two heads and is designed specifically for macro photography suitable for any environment the stf 8 comes with a dust splash and freeze proof 10deg construction and when using the two heads together features a guide number of 85 or 6 when firing a single head the bundled adapter ring is compatible with the olympus mzuiko 30mm f35 macro 60mm f28 macro and 12 40mm f28 pro lens