You're looking for a small sandwich box. You might find some SWAG inside, so feel free to leave something fun for the next geocacher if you'd like. Also, BYOP!
Start your adventure at the trailhead where parking is conveniently available. As you walk down the path, keep your eyes peeled for the hidden treasure waiting to be found. You'll have to navigate through some overgrowth. Watch for muggles during the day.