About Indera Mills From the beginning Indera Mills was a vertically integrated apparel manufacturer specializing in circular knitted underwear garments. Early products included knitted slips and vests union suits knee warmers and bathing suits. Over time the company refined its product offerings and today focuses primarily on winterweight products. The Indera Mills mission is to be the premier thermal underwear supplier in the U.S. by offering the best product value style and quality at a very competitive price. Indera's products of thermal underwear and winterweight rib underwear are available in various colors and styles for men women boys and girls.