Regal Chemicals Metal ID Tag 4-12 per Pack

REGAL® Metal Identification Tags are the most cost-effective and simplest way to detect the presence of stain-causing metals in pools & spas. Keep a tag attached to the pool or spa skimmer basket until it changes color, indicating when metals are present and action is needed. Identifies copper, iron, cobalt and nickel.  Mfg. Part #:47252760