GSI NTB Non-Tilting Outer Barrel for Tokyo Marui G17 Gen 4 MechLabs Engine and a thread protector is

and a thread protector is included

Dimensions (Length x Diameter x Height)

This covers all three of those points

or MTW-SA-409)

GSI NTB Non-Tilting Outer Barrel for Tokyo Marui G17 Gen 4 MechLabs Engine and a thread protector isUpgrade your MARUI G17 Gen4 with the NTB (Nozzle Top Cylinder) to attach accessories and improve accuracy during your airsoft games. This innovative accessory allows you to maintain operability even when a silencer and auto tracer unit are attached, providing flexibility and customization for your gameplay. With no interference with the slide, the NTB results in faster operation, increased gas efficiency, and a higher number of shots. Additionally,