Broken blender jar? Don't toss that Oster blender base! This Blendin replacement glass jar is exactly what you need to get back to making smoothies, sauces, and frozen drinks. The 5-cup capacity is perfect for most family-sized blending jobs, and the square top design fits Oster models that have that little square pin on top of the motor. Important sizing info: make sure your blender's motor opening is 3 3/8 inches and the blade base measures 2 5/8 inches in diameter. This jar works with tons of Oster models including the Classic Series, Heritage Blend, 10-Speed Blenders, and many more (check the massive compatibility list!). The 4-inch square opening makes it easy to add ingredients while blending, and the glass construction means it won't stain or absorb odors like plastic jars can. Just remember - this DOES NOT fit Pro 1200 or Versa models, so double-check your specific model before ordering. Installation is straightforward - just align the square top with your blender base and you're good to go. Much cheaper than buying a whole new blender, and the glass jar actually gives you better visibility while blending. Perfect for anyone who wants to extend the life of their trusty Oster blender!