This wire will become rigid and return to straight when exposed to temperatures above 40ºC (barely hot water, lighter, heat gun, etc). Yes - it comes pre-trained STRAIGHT from the factory which is how you want it. You can re-train it if you want by heating it to elevated temperatures (150-250ºC) in the new desired shape. The wire has a lustrous titanium color (dark grey) with a bluish oxide tint on its surface. When freshly cut, the inner core is nickel white. Nitinol is very abrasion resistant and has self-healing properties, so the wire is quite hard to cut and kink. It feels very smooth and shiny to the touch. It does not require any special handling or protections from oxidation or moisture, and is non-toxic. Do not over heat it, as that will damage the property. If you are using electricity instead of hot water to activate it be sure to use a current limiting circuit. Sold by the foot; quantity of 1 corresponds to 12 inches or 31 cm.