The AREX Delta gen.2 is available in three basic variants but each may be ordered in factory Optics Ready configuration enabling you to further enhance the pistol with a reflex optical sight. The most compact - M variant is practically identical in size to the first generation AREX Delta and reverse grip frame compatibility has been maintained for your convenience. Modular design enables you to customize the firearm to your needs and preferences. Removable front and rear frame inserts incorporate slide guides and hold the complete fire control mechanism yet only the front insert is a serialized part that must remain with the firearm while everything else may be customized or exchanged if necessary or desired.