Waterproof sleeve pipe generally refers to wall penetration sleeve. Wall penetration sleeve is also known as wall penetration pipe, waterproof sleeve, pre-buried wall pipe. Waterproof sleeve pipes are divided into rigid waterproof sleeve pipes and flexible waterproof sleeve pipes. In electrical applications for conductivity, it is called AC wall penetration sleeve. Depending on the material, it can be classified into dry-type capacitor AC wall penetration sleeve and porcelain-insulated AC wall penetration sleeve, abbreviated as silicone rubber sleeve and porcelain sleeve, respectively.