The latest grip for Steyr Mechanical Triggered Air Pistols where a 50mm locking rod is used (2016 onwards)
These fit the Steyr EVO10 and LP2 Compact out the box as these both use a 50mm locking rod.
Any pistol prior to 2016 (other than the LP2 Compact) will have the old 65mm locking rod installed and are therefore only compatible with the old style grips.
It is possible to fit a new style grip to an older pistol, but you will need to order the 50mm locking rod with the new grip and swap it over. This will require the use of a punch to knock out the old rod, before the new one can be installed.