T-N.T. Studio APS-X Hop Up System VSR H+ Kit for VSR-10 (430
Using state of the art engineering, T-N.T. Studio has designed a new kind of barrel that will not only improve accuracy, but improve performance and range by 30-50 percent. T-N.T. inner barrels are uniquely designed from tight bore to wide bore. Specially designed grooves will create an air cushion that will guide the BB while shooting out of the barrel eliminating the contact of the BB with the barrel itself therefore eliminating the deviation usually created by it.
The H+ refers to the inner barrel design as the external diameter of the inner barrel is thicker in comparison to a regular inner barrel which they suggest has far better shock resistance. This in turn won't affect the BB as much as it travels through the barrel, eventually improving accuracy and consistency.