A4Tech MOP-18 Mini rot. Device interface: USB+PS/2, Movement detection technology: Optical, Movement resolution: 400 DPI. Mouse dimensions (WxDxH): 53 x 89 x 33 mm. Compatible operating systems: Windows98/ME/2000/XP(X64)/2003(X64)/MCE2005/Vista X86&X64 Mac OS 9.X-10.X