For this series of rigid borescopes, we have two models with different probe length, 24" long (Model: GB-460) and 12" long (Model: GB-430). 
​Vividia GB-460 USB Digital Manual Focus Gun Barrel Borescope is specially designed to inspect rifle gun barrels with its small diameter (4 mm), and long insertion tube length (24", or 60 cm). Vividia GB-460 USB Digital Manual Focus Gun Barrel Borescope also features manual focus capability, so end users can adjust focus to get better images. With USB connection, Vividia GB-460 Borescope can be used with Windows PC, Mac, Android phones and iPhone/iPad (with extra wireless converter like Vividia VA-B2 AirBox Wireless Converter) to do preview, take pictures and videos. One can use software to do measurement if needed. Side mirror (4.5mm diameter) can be used to inspect wall of barrel in details. The 4mm (0.158") diameter camera probe can fit .17 caliber and large gun barrels. Vividia GB-430 Digital Borescope is a short version with 30cm (12") long insertion tube.
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Technical Specs:
  • Diameter of probe:  4mm, i.e. 0.158"
  • Length of probe:      60cm, 24"
  • Focus range:           Manual focus adjustable 3mm to 100mm
  • Probe material:       metal aluminum
  • Camera resolution:  1280 x 720 
  • Video format:          avi
  • Picture format:        jpg
  • Frame speed:          30 fps 
  • Connection interface: USB 2.0 
  • Compatible with:     Windows (xp/7/8/10), Mac, Android 
  • iOS compatibility:    Yes, need separate wireless converter and suitable app on Apple App Store  

What is included: Vividia GB-460 Borescope; Aluminum carry case; 2 pcs side-viewing mirrors; USB adaptors (micro USB and USB-C); user manual; Downloadable software and apps.  
Structure of GB-460 & GB-430
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USB connection to different operating systems and devices
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Looking inside gun barrel with GB-460 or GB-430 Gun Barrel Borescope: ​rifling, grooves and lands, chamber, gas port, gas port hole