NO COMPROMISES
BUILT FOR REAL DEVELOPMENT
After over a year of testing, iteration, and feedback led by Trevor Bauer, we eliminated the flaws athletes deal with in existing plyo balls. This is a complete throwing development system designed to improve arm speed, command, and feel across all levels.
HUMIDITY-RESISTANT GRIP
Good grip shouldn't fail when you sweat. Our engineered surface maintains its feel in sweat, heat, and outdoor conditions. No slipping, no over-gripping, and no inconsistency.
DUAL FEEL SYSTEM
One side features clean, functional seams for grip and pitch feel. The opposite side is completely smooth for constraint-based training. Adapt your grip instantly depending on the drill.
FULL WEIGHT SPECTRUM
A complete overload to underload progression in one system. Covering 3.5 oz up to 4 lb, this set eliminates gaps and covers all ages, hand sizes, and development stages.
THE BLUEPRINT
ELIMINATING THE FLAWS
Most plyo balls force tradeoffs: durable balls feel bad, and good grip fails in humidity. We built the first set designed to solve all of it at once.
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OPTIMIZED DURABILITY & REBOUNDBuilt to withstand high-volume throws against hard surfaces. The wall thickness is dialed in for a balanced rebound profile, ensuring the balls don't ricochet uncontrollably back at you.
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HIGH-VISIBILITY COLOR SYSTEMA chaotic facility requires clean organization. We utilize bright, distinct colors for easy weight identification during training, resulting in a cleaner, faster drill flow.
BUYER’S GUIDE
THE RIGHT SYSTEM
If you're serious about improving your arm, you don't need more equipment. You need the right system. Here are the exact answers regarding our 7-piece setup.
The 7-piece set includes a complete overload to underload progression: 4 lb, 3 lb, 2 lb, 1 lb, 8 oz, 5 oz (regulation), and 3.5 oz (underload). A mesh carry bag is also included for transport.
It is a dual-texture surface. Half of the ball features realistic, raised seams to build a better feel for pitch shapes. The other half is completely smooth, which is ideal for cleaning up movement patterns through constraint-based training.
No. The composite shell features a humidity-resistant engineered texture that maintains its grip in sweat and high heat. You will not have to over-grip to compensate for moisture.
It is designed for pitchers training velocity and arm care, athletes on structured weighted ball programs, and coaches running throwing development who want one cohesive system.
No. Because we cover the full weight spectrum from 3.5 oz to 4 lb, this single system covers every athlete, hand size, and development stage without you needing to piece together mismatched sets.
THE 4APP DIFFERENCE
STOP SETTLING FOR FLAWED TOOLS
Every plyo ball on the market forces a compromise. We eliminated the friction from throwing development, creating a system that finally works exactly how you need it to.
| Feature | 4APP Half-Seam System | Standard Plyo Balls |
|---|---|---|
| Grip & Feel | ✔ Humidity-resistant engineered texture that maintains a clean, consistent grip in sweat and heat. | ❌ Slippery materials that fail in humidity and force players to over-grip. |
| Seam Functionality | ✔ Dual Feel System offering both clean, functional seams and a smooth side for instant drill adaptation. | ❌ Seams that are either too aggressive and cut your fingers, or entirely nonexistent. |
| System Completeness | ✔ A comprehensive 7-piece set ranging from 3.5 oz to 4 lb with absolutely zero weight gaps. | ❌ "Incomplete, mismatched sets that force athletes to piece together different brands to get the weights they need. |
