Swarovski's 1.7x Magnification Extender amplifies the magnification available to the ATX/BTX/STX modular spotting scope system. Compatible with all configurations of ATX, BTX, and STX and 65mm, 85mm, and 95mm objective lenses, the Magnification Extender acts like a photographic Tele-Converter, mounting in between the objective and viewing modules. Magnification Extender Working Magnification GuideATX/STX with 65mm/85mm Objective: 42.5x-102xATX/STX with 95mm Objective: 51x-119xBTX with 65mm/85mm Objective: 51xBTX with 95mm Objective: 58x Swarovski Optik Swarovski ME 1.7x Magnification Extender 49230