The biggest difference is that RSA-Pro™ surface treatment incorporated a vapor deposition type process that used ionic bonds with silanes to achieve hydrophobicity of the RSA glass and the RSA-Pro X™ surface treatment uses a very different, proprietary process of covalently bonding hydrophobic materials to the walls of RSA™ vials.

The RSA-Pro™ treatment is not very hydrolytically stable and could not be autoclaved or frozen and available only as a custom order item. RSA-Pro X™ will not lose its hydrophobic nature for years, even in the presence of water and they can be autoclaved and frozen and thawed effectively.