Professional-grade bracelets typically utilize natural essential oils such as Citronella, Lemongrass, Peppermint, and Geraniol, or synthetic repellents like DEET or Picaridin. For B2B sourcing, prioritize slow-release technology (micro-encapsulation) which ensures the repellent remains effective for 200 to 300 hours. Additionally, check if the product uses ultrasonic technology, which mimics the sound of male mosquitoes to repel females, though chemical-based options generally have higher market demand.