4. Perceptions related to HIV self-testing: 1) positive attitudes toward HIV self-testing (e.g., convenient, privacy, etc.), 2) negative attitudes toward HIV self-testing (e.g., difficulty to interpret testing results by oneself, inadequate accuracy, etc.), 3) perceived subjective norm related to HIV self-testing (e.g., whether significant others would support them using HIV self-testing), 4) perceived behavioral control in using HIV self-testing, 5) behavioral intention to use HIV self-testing under different scenarios, 6) perceived importance of online real-time counseling supporting HIV self-testing and 7) preference of HIV self-testing kits (blood based or oral fluid based).