It is suitable for the 16cm extended outer tube of the 14 reverse tooth outer tube. There are threads at both ends of the tube, one end can be screwed on the outer tube, and one end can be installed with noise reduction, fire cap, etc. Suitable for water guns with an inner diameter of 9.5mm. Attention! Because the threaded connection is weak, you must use a better layer of consumables, such as petg, so as to avoid breakage, and do not use too much force during installation to avoid thread breakage!