Copper Naphthenate Internal Treatment 8% (68% by Volume) Concentrate (QNAP 5 Gallon Jug). After diluting to 2% with a carrier such as #2 Diesel, this preservative is injected under pressure into poles that have decay or insect voids present. After identifying the void area, preservative is applied using a special nozzle. The oil-based preservative penetrates deeply into all areas and will protect against future biological attack. A contact insecticide may also be added. Always read and follow EPA label directions. - Call for Pallet Quantity Pricing, 719-685-0333.