Achromatic 5X Barlow Lens Pro Slokey SkyWays - Superior Optical Quality with FMC and Anti-Reflective Treated Lens for a Sharp, Crisp, Clear Image - Super Light, Compact and Durable (1.25"): Amazon.co.uk: Electronics
Celestron Luminos 2.5X 2 Inch Barlow Lens - Bristol Cameras
Barlow lens | What they are and how to use one | BBC Sky at Night Magazine
Barlow lens | What they are and how to use one | BBC Sky at Night Magazine
NEEWER 2X Barlow Lens for Telescope Eyepiece, 1.25” Multi-Coated Metal Lens to Double Magnify Eyepieces with M42 Thread to Connect to DSLR or SLR Camera: Amazon.co.uk: Electronics & Photo
Barlow lens | What they are and how to use one | BBC Sky at Night Magazine
Achromatic 3X Barlow Lens Pro Slokey SkyWays - Superior Optical Quality with FMC and Anti-Reflective Treated Lens for a Sharp, Crisp, Clear Image - Super Light, Compact and Durable (1.25"): Amazon.co.uk: Electronics