M110 × 1 extension tube 35 mm for ESATTO 4" (PrimaLuceLab, SKU: PL3600325 ) increases the working distance (back-focus) of the ESATTO 4" focuser by a precise 35 mm. The tube has an M110 × 1 external thread on one side and an M110 × 1 internal thread on the other, so you can screw any accessory (rotator, corrector, camera) between the focuser without losing axiality and mechanical stiffness.

Key Features

• precise optical length of 35 mm – easy setting of the required back-focus
• Threads: M110 × 1 male (extractor side) / M110 × 1 female (accessory side)
• full 96mm internal diameter – no vignetting for full frame sensors
• CNC milled body made of 6061-T6 aluminum, hard anodized - lightweight and corrosion resistant
• blackened, grooved interior - effective reduction of reflections and improvement of contrast

Set components

• spacer sleeve 35 mm M110 × 1

Technical parameters

• input thread: M110 × 1 (female)
• output thread: M110 × 1 (male)
• optical length: 35 mm
• Inner diameter: 96 mm
• material: aluminum 6061-T6, anodized
• Compatibility: ESATTO 4" extractor and accessories with M110 × 1 thread
• EAN: 8059020774004
• manufacturer: PrimaLuceLab – Italy

The PL3600325 is a fast, precise way to achieve additional back-focus in astrophotography setups with the ESATTO 4" focuser, without compromising on aperture and mechanical stability of the optical system.