locking cylinder , homing design , strong spring , automatic homing during each expansion , positive and positioning cylinder , accurate homing Manual tube expander , with the simplest structure for tube expansion , easy to use , compact and easy to carry , suitable for maintenance site , can achieve rapid expansion It is carbon steel with high hardness , waterproof , antirust and resistance 360-degree rotatable handle , strong portability , automatic positioning of steel balls It is applicable to copper pipe and aluminum pipe The pipe specification is 6-22mm, Manufacturer: Watreketal