PU (Polyurethane) coated wheels are commonly used in a variety of applications, including inline skating, longboarding, skateboarding, and material handling equipment. The hardness of PU wheels is typically measured on the Durometer A scale, with lower numbers indicating softer wheels and higher numbers representing harder wheels.

The benefits of softer PU coated wheels include:

1. Better Grip and Traction: Softer wheels tend to provide more grip and better traction because they deform more easily under pressure, allowing them to conform to the surface they're rolling on. This can be especially beneficial on rough or uneven surfaces where the wheel's ability to maintain contact with the ground is crucial for stability and control.

2. Shock Absorption: Soft wheels have superior shock absorption properties, which can make for a smoother ride over bumpy or imperfect surfaces. They can absorb vibrations and small obstacles, reducing the impact felt by the rider or the machine operator.

3. Increased Comfort: Because of their shock-absorbing qualities, softer wheels can offer a more comfortable ride, which is particularly important for activities like inline skating or longboarding where comfort can contribute to performance and enjoyment.

4. Enhanced Maneuverability: Softer wheels can sometimes provide better cornering and turning capabilities because they can flex and grip the surface as you lean into turns. This can be advantageous for tricks, freestyle skating, or navigating tight spaces.

5. Slower Speeds: Softer wheels generally roll more slowly than harder wheels due to increased deformation and energy absorption. For some users, this can be a benefit if they prefer or require a slower, more controlled speed, such as beginners or those using the wheels for specific tasks that don't require high speeds.

6. Surface Adaptability: Soft wheels are more adaptable to different types of surfaces. They perform well on both smooth and rough surfaces, making them versatile for various environments.

It's important to note that while softer wheels offer these benefits, they also wear out faster than harder wheels, which is a trade-off to consider depending on the intended use and frequency of use. Additionally, the choice between soft and hard wheels should be based on the specific needs of the application, the type of surface being used on, and personal preference.