This replacement magazine is a factory original from EAA and fits models manufactured prior to 2005. Factory replacement parts are manufactured to the exact same specifications and tolerances and use the same manufacturing materials as the original parts which guarantees excellent fit and reliable operation.
Keeping a few extra factory magazines around is never a bad idea; extra magazines save loading time at the range and also serve as a backup for those days when you simply cannot remember where you put your primary magazine.
EAA made a running change to its frame sizes in 2005, and ordering incorrect magazines is a very common problem.
Small frame (Pre 2005) approximately 0.796" thick and approximately 1.25" long.
Large frame (Post 2005) measure approximately 0.843" thick and approximately 1.369" long.