Micromall(&trade;) Cmos Memory Battery Compatible with IBM T20 T40 T60 X30 R40 R40e R50 02k6541 02k7087 02k7075 08k8050 08k8216 02k6572 92p0991 92p0986 IBM Thinkpad 570 Series: 570 570e 570x 570z IBM Thinkpad a Series: A20 A20p A20m A21 A21e A21m A21p A22 A22m A22p A23 A30 A30p A31p IBM Thinkpad T Series: T20 T21 T22 T23 T30 T40 T41 T42 T43 IBM Thinkpad R Series: R40 R40e R50 R50e R50p R51 R52 IBM Thinkpad X Series: X30 X31 X32 IBM Xseries: 300 400