schillerI never received mine back as UE keeps it on file after they digitize the impressions, I believe. They use the same impressions so if you should ever purchase a new model, or need repair done, it's one less step in the process. My impression for my UERM was perfect. The same impression was used for my UE11pro and since UE already had them on file, turn around time was relatively quick with the same perfect fit. Impressions should last a while unless one drastically looses/gain weight. Still, it doesn't hurt to ask UE the question. I've had ciem made by other companies who returned the impression, but they are unusable as it has been manipulated and coated with wax.