Keep fog, dew, and condensation from forming on your camera or telescope lens with this Neewer 23.6" USB Lens Heater for Camera & Telescope Lensesfrom Neewer. The heating strap wraps around lenses up to 150mm in diameter and warms the glass with power supplied by an integrated 4.9' cable to a 5V/2A USB-A port. The temperature regulator provides three settings: High Mode (131-149°F), Middle Mode (113-131°F), and Low Mode (95-113°F). The warmer secures around your lens via touch fastener. In a pinch, it can warm up a baby bottle or a  cup of coffee, too.

Prevents Dew, Fog & Condensation    19.7" Effective Length    For Lenses up to 150mm Diameter    4.9' Cable    Temperature Regulator with 3 Settings

Related Questions and Answers

Q: 1. Can this thing be used in Alaska to prevent lenses from frosting?

A: The Neewer 19.7" USB Lens Heater for Camera & Telescope Lenses can help prevent frost on lenses in most weather conditions.

Q: 2. are these Lithium batteries?

A: Yes, the Neewer EN-EL15c Batteries and USB Charger Kit are lithium batteries.

Q: 3. I have the lens dock ... loaded the Sigma software ... was able to check for firmware updates for the 3 Sigma lenses I have it works with/35 art/24/105 art/150-600 c. Thing is, unless I missed it, NOT ONE WORD in the instructions, or on the software on the PROCEDURE for fine tuning. Did I miss it? How is it done - step by step, anyone. Or where to find the PROCEDURE for fine tuning the autofocus.

A: The Sigma dock will allow you to update the firmware of a lense and to set auto-focus finetuning for multiple distances and, in the case of zooms, multiple focal lengths. The settings you enter are written to the lens, so it will have to be recalibrated if you use it on a different camera. The dock does not have a way to test the accuracy of your lens' auto-focus. For that, you need to buy something like the SpyderLensCal calibration tool or use a diy setup.

Q: 4. Does the Sigma 50-500 HSM lens require firmware updates?

A: Unfortunately, this dock is only compatible with the newer Art, Contemporary or Sports series lenses from Sigma with a Nikon F mount.

Q: 5. Can a Sigma Dock be used with a Tamron Lens?

A: No , only with limited amount of Sigma lenses

Q: 6. Have Sigma 18-200 older version. Does not autofocus on D5500. Will firmware update solve this?

A: No, you cannot update the older 18-200mm.

Q: 7. Has anyone used the dock on the Art 14-24 f2.8? If so, did it help or make a difference? I have a D850 and a D500 but only use the lens on the D850.

A: The doc allows firmware updates which may improve certain general or specific performance aspects of the lens. Keeping firmware up to date is recommended.

Q: 8. Will the dock work with the Sigma 18-300mm f/3.5-6.3 DC MACRO OS HSM Contemporary Lens and/or with the Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary Lens on a Nikon dslr body? I was under the impression it worked with all Contemporary lenses.

A: Thank you for your interest in Sigma products. The USB Dock for Nikon Lenses is compatible with the Sigma Global Vision lenses(Art, Contemporary, Sport) except DN lenses.

Q: 9. Is this compatible to Sony E Mount's Sigma 18-300mm lens?

A: Thank you for your interest in Sigma product. As of now, Sigma doesn't make a USB dock nor an 18-300mm lens in E_mount. This product is compatible with Sigma SGV lenses for Sony A-mount.

Q: 10. Does it work fot sigma 24-702.8DG HSM?

A: As long as its the Nikon version of the lens it will work.