L10 is the expected time or the number of operations after which 10 % of the supervised products have failed.
It's widely understood that L10 covers a really huge amount of devices.

Currently Hirschmann doesn't publish any other values than MTBF. But based on the sold/installed devices worldwide and the ones sent back for repair we internally continuously supervise our quality, to react with countermeasures in case the quality drops. The database contains information of at least the last 15 years. E.g. the product family RS20/30 currently has a statistical failure rate after 5 years of operation of 0.55 %. Because this is dependent on the installation, i.e. environmental conditions such as temperature and vibrations, these values vary and cannot be representative for any other application. But this doesn't mean that we guarantee anything else than the MTBF value.

Considering the above example it's obvious that L10 is not measurable within the Product Life Time (time products is sold).