Rotary Corp
1/2" Closed Spoon, Ryan 522361, Blue Bird 71910, Fits Model Lawnaire IV, 7-5/8"L, Classen. 0.090 O.D. 30 Required For a Complete Lawnaire IV Plus Aerator Set, 42 Required For a Complete Lawnaire V Plus Aerator Set. Fits Blue Bird models 424, 530A and 742