$25 - $50

93618 M42 Spacer Kit by Celestron

To achieve the best astroimages, it is important to attain the proper back-focus distance for your camera relative to the telescope it is being used with. If the back-focus distance your camera consumes is not exact, the performance at the corners of full frame imaging sensors will suffer—stars will appear elongated and not as pinpoints.

Example: RASA 8 with a ZWO ASI 183 MC PRO camera

• Required back-focus distance for RASA 8 with included M42 camera adapter: 25mm
• Back-focus consumed by ZWO ASI 183 MC PRO camera: 17.5mm
• To achieve equal back-focus distance, a 7.5mm M42 spacer ring is required

Celestron's M42 Spacer Ring kit includes three different length spacer rings to achieve the proper back-focus distance with our popular Celestron optical tubes and T-thread camera adapters.

How to Use

Depending your method of astrophotography (DSLR or CCD/CMOS), there are two ways to use the M42 Spacer Ring. If you are using a DSLR, place the desired M42 Spacer Ring between your T-Ring and your T-Adapter for your optical tube. If you are using a CCD or CMOS camera, place the desired M42 Spacer Ring between the camera and the T-Adapter for your optical tube.

Body

The M42 Spacer Rings are machined aluminum black anodized. The internal surfaces are blackened and glare-threaded to provide the highest contrast. Each spacer ring has a knurled surface, providing a great gripping surface for threading/unthreading. The M42 Spacer Rings are compatible with M42 x 0.75 (T-thread) camera adapters.

• Adjusts back-focus between your camera and telescope for the best astroimaging results
• Kit includes 3 spacer rings of different lengths (7.5mm, 12mm, 30mm)
• Threads to your T-Ring and T-Adapter with standard male and female T-Threads

10-107-40 Sulfur Dioxide Colorimetric Gas Detection Tube, 0.2 - 5 % (10 Tubes / Box) by RAE Systems

RAE Systems colorimetric gas detection tubes enable quick, on-the-spot measurement of a wide range of toxic and combustible gases and vapors. RAE Systems tubes are easy to read, and provide a sharp, clear color change directly corresponding to the concentration of gas present. RAE Systems tubes are compatible with the RAE Systems piston hand pump, a reliable way to draw samples of an exact volume required for the most accurate measurements.

Key Features

• Wide assortment of tubes available to detect over 300 gases and vapors
• Easyto use, even in multiple layers of gloves
• Easy-to-read with sharp,clearcolorchange
• No calibration or other maintenance required

Applications

• Oil and gas
• Chemicals and petrochemicals
• Agriculture and pestcontro
• Food and beverage production
• Environmental protection
• Fire service
• HazMat response
• Nationalsecurity

SCT-108.001.23 SCT-THYG-PEN-3 Jumbo Dual Display Thermo Hygrometer by ScichemTech

Features:

• Reliable SCT Pocket Type Meter for Humidity & Temperature measurements.
• Comfort / Warm / Cool index with Dual Display.
• Option to select °F/°C.
• Maximum/ minimum (°F /°C) temperature & humidity memory recalling
• 3 m sensor wire with probe for outdoor measurement
• Indoor / Outdoor Temperature & Humidity Display.
• Battery operated.
• With Flipout Stand

*Please note we can only ship RKI products to customers within the United States

*Please note we can only ship RKI products to customers within the United States