non-toxic swimming pool anti-freeze - 1 gallon unknown premium swimming pool anti-freeze with a -50 degree burst protection rating. 1 gallon bottle. non-toxic propylene glycol anti-freeze protects your pool plumbing from freeze damage. safe for swimmers and can be released into the pool in the spring. can be used on all types of pool plumbing. one gallon treats 10 feet of 1.5 inch pool plumbing. we reserve the right to ship best product across multiple manufactures.