Gtechniq W4 Citrus FoamW4 Citrus Foam is a pH neutral formula that removes hard to shift grime, without damaging sealants, coatings or waxes. It combines an effective citrus degreaser with a strong foaming agent making it tough on road grime and bug spatter, but kind to waxes and coatings. It can be used at a dilution of up to 1: 400 through a foam lance, or up to 1: 25 through a pump sprayer. Storage and use We recommend to use in conjunction with a jet wash and snow foam