Caliber: 9mm. Capacity: 10-, 11-, and 13-round magazines. Barrel: 3.0”. Grip: Textured polymer with modular backstrap. Sights: White dot front, notch rear. Length: 7.28” overall. Weight: 18.5 oz. unloaded. Finish: Matte black. Striker-fire trigger. The T.O.R.O. model comes with a red-dot optic. The XL models have 3.7” barrels. Values are for the standard GX4 model; add 17% for the GX4 T.O.R.O. model; add 27% for the GX4 XL model; add 33% for the GX4 XL T.O.R.O. variant.