400 NBS & LEVEL 3:

The compound and flexibility of the outsole is the main thing you’re looking for in a good shoe. You don’t want your outsole to crack or to yellow easily due to lack of rubber or PVC excess. 400 NBS is a measure that shows the resistance and flexibility of a rubber compound. A higher NBS means more grip and flexibility. Common shoes have 200 NBS, making them less lasting. We also offer this option for those clients who need higher shoe quality.