The perfectly compatible SOC stay-on case protects the BTX eyepiece module from impact, knocks and bumps. This does not restrict its handling. Swarovski BTX Eyepiece Module Stay on Case Perfectly protected The perfectly compatible SOC stay-on case protects the BTX eyepiece module from impact, knocks and bumps.This does not restrict its handling. Innovative and perfectly tailored accessories not only enhance the capabilities and functionality of your SWAROVSKI OPTIK spotting scope, they also help to protect it. User-oriented concepts and design both play an important role.