Check the listing for details. GLB Stain Magnet 2.5lb.. Condition: New. Listed at 37.99 USD. This granular formula quickly eliminates metallic stains from pool surfaces with no need to test the water or close the pool. – Use weekly to eliminate stains, prior to using GLB Sequa-Sol Sequestering Agent. – Compatible with most pool surfaces including gunite, most plaster, concrete, vinyl and fiberglass. – NOT intended for use on pools with black plaster. – Compatible with chlorine, bromine, ozone, biguanide and salt water chlorine sanitizing systems. SHIPPING: We will do our best to ship your order based on the shipping method selected, however in some cases, your shipping method may need to be modified to meet shipping requirements based on the carrier. Our current carriers used are UPS, FedEx and USPS. Please contact us directly through the "Contact Seller" link if you need UPS, FedEx or USPS specifically for your order.