This is NOT a universal part, please see measurements BEFORE ordering Top of cap has 2.75" opening where it screws on to jar Even if your model is listed, please check dimensions shown in pictures before ordering Fits Black & Decker Blender Models BL1900, BL2900, BL3900, BL4900 Fits Black & Decker Blender Models BL5000, BL5900, BL6000, BL9000 Univen BL5000-11 blender jar bottom screw cap. Fits Black & Decker blender models BL1900, BL2900, BL3900, BL4900, BL5000, BL5900, BL6000, BL9000. Top of cap has 2.75" opening where it screws on to jar.