Actually I don't know, the code sayes:

FUSES
 *      I use these fuse settings
 *      Low:  0x75  (4.8MHz CPU without 8x divider, 9.4kHz phase-correct PWM or 18.75kHz fast-PWM)
 *      High: 0xfd  (to enable brownout detection)

But I can't find where it is burned to the MCU

http://bazaar.launchpad.net/~toykeeper/flashlight-firmware/trunk/view/head:/ToyKeeper/blf-a6/blf-a6.c