Amazon.com : 3X Barlow Lens, 3X Astronomical Telescope Eyepieces Barlow Lens with M42x0.75mm Thread, T Ring Adapter for 24.5mm Astronomical Telescope/Digital Camera : Electronics
Celestron X-Cel 3X 1.25" Barlow Lens | Triple Your Magnification
Haofy Barlow Lens,1.25 Inch 3X Magnification Astronomical Telescope Eyepiece Lens With Fixing Screw,for Eyepiece Filters And Other With 1.25 Inch Thread Accessory - Walmart.com