Tele Vue 0.25" Accessory Tube For 2.4" (TLA-0250) 20x Binoculars press the Sky Tour button:

press the Sky Tour button: StarSense will automatically slew to all the best stars

The Baader clear glass filters are used to focus a camera when using very narrow band line filters (due to same mechanical thickness)

the distinctive pattern was invented by Russian amateur astrophotographer Pavel Bahtinov

Dazzling Views with High Quality Optics

Since the T-ring is camera-brand specific

Tele Vue 0.25" Accessory Tube For 2.4" (TLA-0250) 20x Binoculars press the Sky Tour button:0. 25" Length Accessory Tube for 2. 4" adds 0. 250" (6. 4mm) extension between Imaging System accessories. Focuser extensions of various lengths are often used to create the necessary distance for proper spacing of field lenses to imager; the required distance will vary depending on camera specifications. All are black anodized aluminum with anti reflection threads for maximum contrast.