Square Top Glass Jar. Compatible with Oster Models that have the little square pin on top of the motor. It fits models that the outside diameter of the base of the blade is 2 5/8" and motor top opening is 3 3/8". The compatible models are: Heritage Blend, Classic Series, Reverse Crush, Precise Blend, 10-Speed Blender, Rapid Blend, Precise Blend, Pure Blend, Exact Blend, Accurate Blend, and Simple Blend. Again please make sure the top opening of your blender is 3 3/8" to make sure this jar fits it. DOES NOT FIT PRO 1200 OR VERSA MODELS.