Stens 385-744 Trimmer Head for Stihl 4003 710 2108 Replaces: Shindaiwa: 99906-1566 Stihl: 4003 710 2108, 4003 710 2193 Easy to install by using brush blade hardware Can also be used as fixed line head 6 1/4" head diameter 12" cutting diameter Flail head Fits straight shaft trimmers For 1" and 20mm arbors