Good things come to those who wait, and while the Echelon isn't the first polymer pistol to feature a modular design, night sights, and optics mounting system-it might be the BEST. Like the SIG P320, the Echelon is built around a serialized chassis that Springfield calls the Central Operating Group-essentially the "skeleton" of the gun-which can be customized with small and medium grip frames. This allows you to effectively turn the Echelon into a compact or subcompact gun with optional slide/frame combos (sold separately, and available from Springfield soon). But unlike other serialized chassis out there, Springfield's Central Operating Group is considerably sturdier and more rigid, providing an incredibly robust housing for the operating system. Chambered in 9mm 4.5" hammer-forged steel barrel Melonite barrel and slide finish Billet-machined optics-ready slide Central Operating Group modular chassis Tritium/luminescent front sight Full-size polymer frame with medium grip module Striker-fired action Includes Viridian RFX II green dot optic Flat-faced trigger design (3) 17-round and (2) 20-round magazines Includes Springfield range bag 1:10 twist rate Black polymer frame and grip module Optimized for defense, competition, or carry