Measure modes include Maximum, °C/F (Selectable). IRT201, IRT11 add MIN, and Lock. IRT201 Premium features include Average, ? (max-min), hi/low alarm, probe detection, optional K- thermocouple probe. IRT91, IRT201 feature a bright large amber back-lit LCD display and automatic data hold

• Measurement Range (1 second response time)
  IRT91: -58 to 752°F.
  IRT201: -76 to 1400°F, -83.2 to 1999° F with optional K-Thermocouple
  IRT11: -67 to 428°F
• Emissivity
  IRT91: fixed 0.95
  IRT201,IRT11: 0.05 to 1.0/0.01 steps, adjustable
• Power
  IRT91, IRT201:Two "AAA" batteries (included)
  IRT11: Battery (CR2032) included
• Dimensions
  IRT91, IRT201: 6.9" x 1.53" x 2.83"
  IRT11: 3.0" x 1.9" x 1.0"