the entire engine compartment. I'm planning on buying some Hosetechniques stuff soon too. The origional post said: : 20-30 feet of 4mm &: 10-15 feet of 6mm The more you buy, the more you can change out. If you get the maximum amount(30ft:4mm & 15ft:6mm) and ship it UPS ground, it comes out to be a little over $65. Well worth it if you ask me. Hope this helps you any. Later. --Vann