Guide TD421

The Guide TD421 is a robust thermal imaging monocular from the Gen2 series, optimized for detailed observation at mid-range. It features a 384 × 288 VOx sensor with 12 µm pixel pitch and NETD ≤ 35 mK, delivering crisp thermal imaging at a fluid 50 Hz frame rate via its high-quality 0.23″ AMOLED display (640 × 400).

Equipped with a 25 mm f/1.1 lens, the TD421 offers a field of view of approx. 18 m × 14 m at 100 m, and optical magnification between 1.9× and 7.6×. With a detection range of nearly 1,300 m, it's well-suited for users needing fine detail and extended reach.

About the Guide TD Gen2 Series

The TD Gen2 series combines advanced thermal imaging with rugged durability and extended battery endurance. Packed with user-configurable palettes, Picture-in-Picture mode, fast startup, and Wi‑Fi streaming, these devices are engineered for reliable performance in field conditions. IP66-rated and offering up to 10 hours of battery life, TD models strike the ideal balance between precision, portability, and endurance.

Key Features

• 384 × 288 VOx thermal sensor, 12 µm pixel pitch; NETD ≤ 35 mK
• 25 mm f/1.1 objective lens with manual focus
• Field of view at 100 m: approx. 18 m × 14 m
• Optical zoom: 1.9×–7.6×
• Detection range: up to 1,300 m
• Display: 0.23″ AMOLED, 640 × 400 resolution; 50 Hz refresh
• Color palettes: Black Hot, White Hot, Red Hot, Iron Hot, Blue Hot
• Eyepiece: 12 mm eye relief; diopter adjustment −4 to +2; 18× digital zoom
• Connectivity: Wi‑Fi (2.4 GHz) and USB-C
• Power: single 18650 battery; approx. 10 h operating time
• Rugged housing: IP66-rated, shock- and fog-resistant
• Weight: 325 g; Dimensions: 150 × 45 × 74 mm

About Guide Sensmart

Guide Sensmart — part of Guide Infrared — is a global leader in thermal imaging technology, distributing high-quality, affordable thermal optics across more than 70 countries. With over 20 years of R&D expertise, Guide is known for durable, easy-to-use devices that deliver reliable performance in demanding environments.

What’s in the Box

• Guide TD421 Thermal Monocular
• Lens cover and lanyard
• Wrist strap
• Carry bag & eye mask
• Battery charger with 18650 cell
• USB Type‑C charging cable
• Quick start guide & warranty card

Warranty

The TD421 is backed by a 2-year manufacturer warranty, with service support provided through Guide’s global authorized centers.