Compatible with the following Red Wagon Models Model 2700 Pathfinder Model 3101A Ultimate Family Wagon Model 3150 Deluxe Family Wagon Model 3181 Ultimate Comfort Wagon Model 3210 Grandstand Wagon 3-in-1 Model 3215 Deluxe Grandstand Wagon 3-in-1 Model 3300 Passport Wagon Model 3332 Triple Play Wagon Model 3333 Triple Play Deluxe Wagon Model 3900 Ultimate EZ Fold Wagon Model 3951 3-IN-1 EZ Fold Wagon Model 3955 Ultimate EZ Fold Wagon Model 687 Pedal Racer Model 2600 Discovery CAP SIZING In General, these are the Caps needed for each product: 1/4” are for Classic Infant Walker Wagon 3/8” are for Bikes, Tricycles, STEP 2 products 7/16” are for Plastic & Folding Wagons 1/2“ are for Steel & Wood Wagons How to Determine Cap Size Measure the diameter of the axle. IMPORTANT NOTE The 1/2“ CAP is 1/16” larger than 7/16”, so be aware of this when measuring your axle diameter. 1/2 Inch Red 7/16 Inch Red 3/8 Inch Red 1/4 Inch Red Add to Cart Add to Cart Add to Cart Add to Cart Customer Reviews 4.5 out of 5 stars 557 4.6 out of 5 stars 529 4.5 out of 5 stars 704 4.1 out of 5 stars 103 Price $13.99$13.99 $13.99$13.99 $12.89$12.89 $9.95$9.95 Axle Diameter (Inches) 0.5 0.4375 0.375 0.25 Axle Diameter (mm) 12.7 11.1125 9.525 6.35 Color Red Red Red Red Quantity of Caps 4 4 2 4 General Use Steel & Wood Wagons Plastic & Folding Wagons 3/8” are for Bikes, Tricycles, STEP 2 products Classic Infant Walker Wagon and other WALKERS