Hex keys are used to turn bolts and screws with an hexagonal (six-sided) indentation in the fastener head compared to Torx keys that are used to turn screws and bolts with a six-point, star-shaped indentation. Service keys are used to turn fittings and fasteners and are compatible with one type of product or brand to limit tampering. Key organizers are used to hold multiple hex or Torx keys and arrange the tools by size to ease identification and access.