Wire Range: #18 - #12 AWG. Usable Temperature: 105°C, 221°F. Certification: RoHS Compliant, UL Approved, CSA Certified UL-94-2. Flame Retardant Material Compatibility: Solid or Stranded Wire. Positive-grip design for easy installation. Five color-coded models cover hundreds of wire combinations. Tough, thermoplastic shell protects against environmental extremes. The fixed square-wire spring provides a secure connection that won't relax over time. High-dielectric shell features deep skirt design to prevent exposure of bare wire. Resists chemical action from hydrocarbons, diluted acid or alkaline solutions.