Die-cast. For "A" section. 1/2" V-Belts. No. 150A5: Outer Diameter: 1-1/2", Bore Size: 1/2", Type: A No. 175A5: Outer Diameter: 1-3/4", Bore Size: 1/2", Type: A No. 175A6: Outer Diameter: 1-3/4", Bore Size: 5/8", Type: A No. 200A5: Outer Diameter: 2", Bore Size: 1/2", Type: A No. 200A6: Outer Diameter: 2", Bore Size: 5/8", Type: A No. 200A7: Outer Diameter: 2", Bore Size: 3/4", Type: A No. 225A5: Outer Diameter: 2-1/4", Bore Size: 1/2", Type: A No. 225A6: Outer Diameter: 2-1/4", Bore Size: 5/8", Type: A No. 225A7: Outer Diameter: 2-1/4", Bore Size: 3/4", Type: A No. 250A5: Outer Diameter: 2-1/2", Bore Size: 1/2", Type: A No. 250A6: Outer Diameter: 2-1/2", Bore Size: 5/8", Type: A No. 250A7: Outer Diameter: 2-1/2", Bore Size: 3/4", Type: A No. 275A5: Outer Diameter: 2-3/4", Bore Size: 1/2", Type: A No. 275A6: Outer Diameter: 2-3/4", Bore Size: 5/8", Type: A No. 275A7: Outer Diameter: 2-3/4", Bore Size: 3/4", Type: A No. 300A5: Outer Diameter: 3", Bore Size: 1/2", Type: A No. 300A6: Outer Diameter: 3", Bore Size: 5/8", Type: A No. 300A7: Outer Diameter: 3", Bore Size: 3/4", Type: A No. 325A5: Outer Diameter: 3-1/4", Bore Size: 1/2", Type: A No. 325A6: Outer Diameter: 3-1/4", Bore Size: 5/8", Type: A No. 350A5: Outer Diameter: 3-1/2", Bore Size: 1/2", Type: A No. 350A6: Outer Diameter: 3-1/2", Bore Size: 5/8", Type: A No. 350A7: Outer Diameter: 3-1/2", Bore Size: 3/4", Type: A No. 400A5: Outer Diameter: 4", Bore Size: 1/2", Type: A No. 400A6: Outer Diameter: 4", Bore Size: 5/8", Type: A No. 400A7: Outer Diameter: 4", Bore Size: 3/4", Type: A No. 450A5: Outer Diameter: 4-1/2", Bore Size: 1/2", Type: A No. 450A6: Outer Diameter: 4-1/2", Bore Size: 5/8", Type: A No. 450A7: Outer Diameter: 4-1/2", Bore Size: 3/4", Type: A