Anti-lime stem ball Stem and ball are manufactured in one whole piece made of anti-lime polymer, which increases its resistance and performance, avoiding lime effects. This original arco 's component has been designed to reduce loss of pressure, keeping a constant flow rate and avoiding noise. As well ball-stem's quarter turn system has the same fundamental features of leak tightness and low loss of pressure that you can find in the a-80 series. The anti-lime stem-ball is the perfect solution to prevent lime problems, that can render useless the valve, and - maintain the flow rate constant along the time, avoiding the lime to adhere, reducing the water flow. Internal leak tightness The supporting clip made of pom is placed in the valve to push the nbr seal against the stem-ball. This system cannot be dismantled, avoiding improper manipulations. External leak tightness A double nbr seal placed on the stem assure external leak tightness. This double joint system guarantees safety against external leakage, use, ageing, etc. Handle The handle includes an additional uv protection that allows its outdoor installation, keeping all the mechanical properties along the useful life. Specifications: 1/2" bsp- inlet 3/4" bsp - outlet Anti-lime protection Taps are operated by a quarter turn