- COMPATIBILITY: Designed specifically for Standard Oster Classic Duralast Blenders with a motor base opening of 3 3/8 inches. Fits models with an outside blade diameter of 2 5/8 inches. Not suitable for Pro, Master, or Versa models. - REPLACEMENT PART: This Black Blender Jar Bottom Cap Base substitutes for Part 4902. Constructed with rugged plastic gear and includes a reliable gasket, ensuring your ingredients stay securely in the blender jar. - SILICONE RUBBER O-RING GASKET: Made from durable silicone rubber, this gasket offers excellent elasticity and a secure seal. A perfect replacement for the original gasket that may degrade over time due to wear and tear. - REPLACEMENT BLADES: Features an Ice Crushing Blade that replaces original Part 4961. Crafted from stainless steel, this sharp blade effectively crushes ice and blends ingredients for smooth results. The motor's alternating blade motion helps draw food and ice down for consistent blending. Use Cases: 1. Ideal for making smoothies, ensuring a perfectly blended consistency without large ice chunks. 2. Perfect for preparing frozen cocktails, easily crushing ice for refreshing drink recipes. 3. Great for soups and sauces, providing a reliable seal and maximizing blending efficiency.