Here's an excerpt from Ten Ren's website.
TenRen's King's Dark Oolong Super Fine consists of the finest oolong harvested during the premium seasons, spring and winter, and from the best area to grow oolong, the mountains of central Taiwan. Each tea leaf is handpicked to ensure harvests of young terminal buds. The steeped tea has a light golden brown hue, prominent roasted aroma with sweet undertones, the initial flavor of roasted chestnuts, and a strong lasting, sweet and roasted aftertaste which lingers at the back of the throat.
The water used to steep this tea should be about 185-195°F or 85-90°C. Use about 2 teaspoons (3 g) of tea leaves for about every 5 ounces (150 mL) of water. A steeping time of about 3-5 minutes with more or less time is recommended depending on the desired concentration. As a rough guide, the higher the temperature of the water or the greater the amount of leaves used, the shorter the steeping time should be. For the ultimate enjoyment, a traditional Chinese Yixing teapot is recommended for loose oolong tea. The teapot should be half filled with leaves and initially steeped for 45 seconds to 1 minute with the steeping time increased by an additional 15 seconds for each successive steeping. The leaves may be steeped multiple times.
Ten Ren's website also gives an overview of their King's oolong tea line.
King's Tea, a TenRen exclusive, is made of high quality oolong tea blended with a touch of ginseng to create an incredible aftertaste. The tea has the rich smooth taste of oolong with an aftertaste which is sweeter and longer lasting than the traditional oolong tea. The bitter tartness associated with ginseng can not be tasted in this tea. King's Tea is offered in two varieties, Green and Dark, each in several different grades. The Green and Dark King's Teas are determined by how long the base oolong is baked, with Dark ones baked longer than Green ones. The different grades depend on the quality of the oolong leaves. Try this unique tea and taste why it is popular in southern Asia.