Sixth Street Specialty Lending is a business development company that provides various types of loans, investments, and equity securities with a focus on co-investments. They invest in industries such as business services, healthcare, energy, and more while targeting middle market companies in the US with an enterprise value between $50 million and $1 billion. The fund invests in transactions ranging between $15 million and $350 million and can arrange syndicated transactions of up to $500 million.