... certificate 3. tolerance:0.05mm-0.2mm 316 stainless steel adjustable base used for sofa1. material: stainless steel2. ISO certificate3. ... one step 1) Material: Steel, Brass, Copper, Stainless steel, Plastic, Aluminium, POM, Delrin, Titanium Alloy etc.2) Surface treatment:Zinc plating ... quality, competitive price and excellent service. FactoryProducts 316 stainless steel adjustable base used for sofa