TEC-HRO tune" is an innovative barrel-extender for your air-rifle !! By placement of "TEC-HRO tune" at your air-rifle, it automatical will extend it to the max. acceptable total-system-length of 85 cm ! For to avert that you have to change your head-positon after mounting "TEC-HRO tune", we constructed them that way, that there is NO diopter-elevation necessary. This way remains the backsight-hight and consequently your head-position individual configurable !! "TEC-HRO tune" consists of 2 parts: "base-system" and "inlay". The base-system fits to nearly all current sport-air-rifles. The corresponding inlay will screws together and extends your rifle during mounting forthwith to the acceptable total-system-length. Should you change anytime your air-rifle (other manufacturer), you only need another inlay and you already can apply your barrel-extender continuing ! The compound to your barrel happens by a fitting exactly clamp connection which the barrel completely encloses. The own weight of "TEC-HRO tune" we constructed aware lowly, at individual weight-variations not to stay in the way. Further preferences of "TEC-HRO tune": reducing of jump-reaction at firing (advantageous drowsiness-performance) longer sight line till to the accepted maximum (consequently more precise target possible) elegantly design