If you have an old IBM laptop computer, IBM is also known as Lenovo or thinkpad model to be exact; if it fit one model below, it will fit all other models listed below. I think this is helpful for bargain shopper not have to pay high prices for certain exact model when you can get cheaper one that would work for the same model. The most important thing is the plug size 2.5mm, volt 16v,  and amp 3-5amp, match it 95% the least to prevent problems.

Compatible to PN: 02K5669, 02K6545, 02K6548, 02K6549, 02K6550, 02K6554, 02K6557, 02K6673, 22P9021, 02K6707, 02K6708, 02K6709, 02k6746, 02K6749, 02K6545, 02K6746, 02K6548. Compatible Models: IBM ThinkPad 600 Series: 600D, 600E, 600X / IBM Thinkpad 365 Series: 365C, 365CD, 365CS, 365CSD, 365E, 365ED, 365X, 365XD / IBM Thinkpad 380 Series: 380CE, 380D-MMX, 380E, 380ED, 380X, 380XD, 380Z / IBM ThinkPad 385 Series: 385CD, 385D, 385D-MMX, 385E, 385ED / IBM ThinkPad 390 Series: 390E, 390X / IBM Thinkpad E530, S31, 240, 240X, 310, 535, 560, 570, 700, 770, 1200, 1300 / IBM ThinkPad A Series: A20, A21, A22, A30, A31, A31P / IBM ThinkPad T Series: T20, T21, T22, T23, T24, T30, T40, T41, T42, T43 / IBM ThinkPad X Series: X20, X21, X22, X23, X30, X31, X32, X40, X41, X41 Tablet / IBM ThinkPad R Series: R30, R31, R32, R33, R50, R51, R51P, R52, R40, R40E, R41 / IBM ThinkPad I Series: i1200, i1210, i1211, i1230, i1241, i1250, i1251, i1271, i1300, i1321, i1340, i1351, i1361, i1391, i1418, i1420d, i1421, i1422, i1460, i1480, i1482, i1500, i1720, i1721.