The exterior of the speaker sits flush with your drywall, giving it a sleek and smooth appearance. Once your in-wall speakers are in place, you can connect it to the power and amplification sources to get that rich, deep sound you want in your outdoor space.
Drying oils will change from liquid to a solid film when exposed to oxygen in the air. Nut oils (boiled linseed, tung, etc.) are drying oils, but vegetable (peanut, olive) and mineral oils are non-drying. Edible mineral oil is popular on food contact items, like cutting boards. However, non-drying oils stay wet indefinitely, and they will wash off when the board is scrubbed with soap and water. Because they do not dry to a solid film, non-drying oils are considered a wood treatment, but not a finish.
White oak is denser than red oak and is an excellent choice for a cutting board. While any wood can be used the goal is resistance to damage caused by the knife. Hard maple seems to be the overall favorite choice. too have read of the mineral oil choice. My daughter has a home-made oak cutting board that over about five years of use has developed a lovely dark patina. I suspect she has never re-oiled it. But hot soapy water seems to be all that it needs to keep it clean.