Liemke Keiler 25.1

• Wide field thermal view: The 25 mm f/1.0 objective and 10.5° field of view make it easier to scan woodland edges, field margins and short-to-medium distances without constantly sweeping back and forth.
• Balanced image detail: A 384x288 VOx sensor with 12.00 μm pixel pitch and 40.00 mK NETD helps reveal heat sources clearly enough for confident spotting in changing weather and cluttered backgrounds.
• Comfortable handheld use: At 445.00 g and 147.00 mm long, the compact housing is easy to carry in a pocket or jacket and remains practical for longer observation sessions.
• Long operating time: Up to 10.00 h of battery life, plus USB-C power support, reduces interruptions during evening hunts and extended outings.
• Recording and wireless connectivity: Image capture, video recording and Wifi let the monocular document observations and share a live view with a mobile device when needed.

About the Liemke Keiler Series

The LIEMKE KEILER series is a family of handheld thermal imaging devices built for hunters and outdoor users who need a compact observation tool rather than a scope mounted to the rifle. Within the LIEMKE range, the KEILER line covers pocket-sized monoculars for scanning game, checking field edges and monitoring movement before taking up a shooting position. The series includes models that differ in detection range, field of view, sensor configuration and lens size, so the range spans both wider-view general-purpose units and models better suited to longer-distance observation.

A defining trait of the KEILER family is its compact format and controls designed for either-hand operation, which suits real field use where quick one-handed handling matters. LIEMKE positions KEILER models for hunting across fields, forests and mountainous terrain, so the series emphasizes practical portability, fast thermal detection and straightforward operation over bulk. Across the family, the concept remains the same: a handheld thermal monocular that is easy to carry, quick to deploy and tailored to observation tasks before, during and after the hunt.

About the Liemke Keiler 25.1

The Liemke Keiler 25.1 is the more compact, wider-view member of the KEILER family, built for hunters who spend much of their time scanning at short to medium distances. Its 2.40 x base magnification works well with the 25.00 mm objective and 185.00 m/1000m field of view, giving a practical balance between target size and situational awareness. In woodland, on field edges or during movement between stands, that wider image helps pick up heat signatures quickly and track animals without losing the surrounding scene.

The thermal core uses a 384x288 VOx Uncooled sensor with 12.00 μm pixel pitch, 40.00 mK NETD and a 50.00 Hz refresh rate. In practice, this combination supports a stable, natural-looking image with enough sensitivity to separate animals from background clutter and enough refresh speed for smooth panning. The 1024×768 OLED display gives the image a crisp, high-contrast presentation that is comfortable to interpret during longer observation periods.

Field handling is a major strength. The housing stays compact at 147.00 mm in length and 445.00 g in weight, so the monocular is easy to carry and quick to raise. A central focusing system, -5/+5 dpt diopter adjustment and up to 10.00 h battery life support practical day-to-day use, while Wifi, image capture and video recording add useful documentation and sharing functions. Waterproof and fogproof construction further suit the Keiler 25.1 to demanding hunting conditions.

About Liemke

LIEMKE has been active in thermal imaging since 2008 and focuses on thermal imaging optics for hunting and outdoor use. The company’s product range includes handheld devices in the KEILER line, clip-on thermal devices in the LUCHS line and the MERLIN thermal imaging series. LIEMKE has developed its own optics since 2014, which reflects a strong specialization in this product category rather than a broad generalist approach.

The brand also integrates practical digital functions, including image transfer to mobile devices through Wi-Fi or cable, which is directly relevant to modern thermal observation equipment. Since 2020, LIEMKE has been part of the Blaser Group, linking the German thermal-optics specialist with a larger hunting and shooting equipment group while maintaining its focus on thermal imaging devices.

Main Features

• Product type: Thermal monocular
• Series: Liemke Keiler
• Made in: Germany
• Magnification: 2.40 x
• Objective lens diameter: 25.00 mm
• Lens aperture: F 1.0
• Field of view: 185.00 m/1000m
• Field of view (degrees): 10.50 °
• Close focus: 1.00 m
• Diopter range: -5/+5 dpt
• Detection range: 1250.00 m
• Thermal sensor type: VOx Uncooled
• Sensor resolution: 384x288
• Pixel pitch: 12.00 μm
• NETD: 40.00 mK
• Refresh rate: 50.00 Hz
• Display type: OLED
• Display resolution: 1024×768
• Image capture: Yes
• Video recording: Yes
• Video output: Yes
• Connectivity: Wifi
• Battery life: 10.00 h
• Power supply: Rechargeable Battery, USB-C port
• Focusing system: Central
• Tripod adaptable: Yes
• Waterproof: Yes
• Fogproof: Yes
• Working temperature range: -20°C to +50°C
• Dimensions: 147.00 x 72.00 x 47.00 mm
• Weight: 445.00 g

Warranty

2 years. The Liemke Keiler 25.1 is covered by a 2-year warranty.

In the Box

• Hand strap
• 1 LIEMKE BP-K Li-Ion rechargeable battery
• Neck strap Slim
• Neoprene cover
• Tripod adapter plate with screws and offset wrench
• Power supply unit with USB-C connection and 4 plug adapters
• Cable USB-C to USB-A
• Lens cleaning cloth
• Instruction manual
• Adapter for LIEMKE carrying strap