Explanation for Model Blank firing protection system control valve (On/Off) Built in auto-greasing system to enhance the durability of breaker Swivel valve Application to prevent the damage of the existing hose Nonstop pin type to prevent tool pin. Improved durability Auto-Greasing System (Open type Option)Increase breaker durabilityAdvance efficiencyGrease easilySwivel Valve Application (Box-type Only)Prevent the damage of the existing hose