The ZRO Delta Modulus is a 9mm pistol kit built around a modern production frame. The kit includes back straps, tools, magwells, and additional slides and barrels, with 4, 4.5 and 5 inch barrel lengths listed. The supplier rates the bores as very good and the finish and grips as very good overall. The item is listed as used, and the kit is meant to be set up either for concealed carry or as a race gun for range day.

This kit suits a shooter who wants one pistol that can change configuration, moving between a shorter barrel and a longer race setup. The extra slides, barrels and back straps give room to match grip size and barrel length. Because the kit is used, check the fit of each slide and barrel combination at the dealer before the firearm leaves the shop.

Key features

• 9mm pistol kit with multiple barrel lengths
• Barrels listed at 4, 4.5 and 5 inch
• Includes extra slides, back straps and magwells
• Tools included with the kit
• Listed as used, very good overall condition

The firearm ships to the licensed FFL dealer you name, where you complete ATF Form 4473 and pass a NICS background check before pickup.