1. Product Overview SP30B heavy-duty ball transfer unit features a 30.16 mm steel ball and durable steel housing, providing smooth 360-degree movement and high load capacity. Ideal for conveyor systems, cargo handling equipment, and industrial material transfer applications. 👉 Get a quote within 24 hours for your project 2. Key Advantages 30.16 mm main ball diameter. Heavy-duty steel construction. Smooth 360-degree multidirectional movement. Low-friction rolling performance.