Intel "Pentium III class" Celeron CPU 600MHz Featuring 128K onboard full speed L2 Cache, 66MHz FSB (Front Side Bus) S-Spec numbers: SL46U, SL3W8, SL4NX, & SL4PB. Core voltages: from 1.5-Volts to 1.7-Volts. Please contact us if you need a specific S-Spec number or voltage.