This internal speaker is suitable for Lenovo ThinkPad laptop models L421, L410, L412, L420, L510, and SL410. It includes left and right speakers with the code 1-SPKR428. It is compatible with various model numbers such as:

• L412: 0530A11, 055333M, 055343M, 05535KM, 05535MM, 05536WM, 05537HM, 055382M
• L421: 0553AK6, 0553AZ8, 0553B15, 0553B56, 0553PM7, 0553PN6, 0553PR7, 0553PW7, 0553R57, 0553R78, 0553R85, 0553R95, 0553RA5, 0553RB3, 0553RH1, 0553RJ1, 0553RU7, 0553RW9
• L510: 2873A16, 2873A25, 2873A61, 2873RU6, 2873RU7, 2873RV3, 2873RW7, 2873RY7, 2873RZ2, 2873RZ7, 2873RZ8
• L410: 2931CTO, 2931RS8, 2931RV1, 2931RW9, 2931RY3, 44036CM, 4403CTO, 4404A43
• L420: 78274RM, 78274TM, 78274YM, 782752M, 782754M, 782755M, 782757M, 782758M

The speaker offers stable sound performance and is ideal for replacing defective speakers in ThinkPad series devices.