Many MBBR media manufacturers and suppliers will provide samples upon request to evaluate quality, size and shape to ensure compatibility with wastewater treatment applications, but it is also necessary to contact directly and discuss the specifics of the project, we will provide samples according to your needs and make improvements according to your requirements until you are satisfied, and also we pay the shipping cost of the samples free of charge, and we will provide you with the best service, if you need, please feel free to contact me！