gallon, medium sheen, original marine sealer, formulated as a traditional exterior tung oil sealer for use only under 2 coats of waterlox original marine finish (tb 3940). tung oil & resin varnish sealer for use on all exterior wood surfaces in direct sunlight/uv exposure as a sealer coat and in conuunction with our waterlox original marine finish (tb 3940), penetrates and waterproofs when used as the ssealer/primer coat(s) in conjunction with waterlox original marine finish (tb 3940). not recommended for use on exterior decks. spread rate: 500 square feet per gallon per coat.