Features: The Universal radiators Step wrenches connectors combines 5 in 1 versatility with a 10-21mm hexagonal head ranges and square connection, crafted from delicate high carbon steel for precise radiators and valves nipple maintenance. Featuring a multiple sized hexagonal design (10mm,12mm,13mm,16mm,21mm) and convenient 88mm length, this tool ensures compatibility with traditional heaters while offering space efficient operation. Produced for plumbers, HVAC technicians, and DIY enthusiasts needing reliable torques control for radiators installations, valves adjustments, or mechanical repairs. Perfect for tight space in residential/commercial heating systems, water supply net works, or industrial equipment requiring secure fastener engagement. Its high carbon steel construction delivers exceptional hardness and wear resistance, making it long time addition to any radiators tool or valves wrenches adapter kit. Specifications: Materials: High Carbon Steel Type:Outer Square/Inner Suqare Outer Square Size: Approx.90mm/3.54inches Inner Suqare Size: Approx.85mm/3.34inches Package Includes: 1Pc radiators Step Wrenches Connectors note: Please allow 1-3cm error due to manual measurement. please make sure you do not mind before you bid. Due to the differences between different monitors, the picture may not reflect the actual color the item.