The SWAROVSKI OPTIK Binocular Booster for all EL 32 and SLC binoculars (except 8x30 WB) doubles magnification. For example, converts the SLC 15x56 WB into a monocular telescope with 30x magnification. Assembly of the Binocular Booster is quick and easy. Simply unscrew one of the two twist-in eyecups and screw on the booster.