IBM X23 - Manual (Page 120)

Battery Li-Ion 6cell Panasonic 02K6760
Battery Li-Ion 6cell Sanyo Japan 02K6845
Battery Li-Ion 6cell Panasonic Japan 02K6846
18 Screw Cap Bottom 04P3528
19 EDC Board 26P8181
20 IRDA Port 26P8168
IR / 1394 Sub card 26P8169
21 Gasket Mini-PCI 802.11b Combo Card 46L4908
116 ThinkPad X20, X21, X22, X23, X24