3/8 inch, Standard  rod, non-tilt spiral balance with plastic carrier shoe attached.

Balance Type: Spiral with small plastic carrier shoe
Tube Diameter: 3/8 inch
Carrier Hole Centers: 1/2 inch center to center
Rod Type: Standard or Extended Rod (1" Longer Rod)
Rod Length: 3/4 inch longer than tube
Tube Length: 10-40 inches 
Bearing Colors: White, Red, Blue or Green
Plastic Carrier Shoe: 5 Different  

NOTE: The difference between 74 & 75 Series is the hole centers for attachment
*  74000 Series has 1/2 inch hole center and uses a plastic Carrier Shoe
*  75000 series has  9/32 inch  hole center and uses metal attachment