The M81 → M65 adapter with stop ring for ESATTO 3" / ARCO 3" (PrimaLuceLab, SKU: PL3600350 ) enables the connection of M65 × 1 threaded accessories to the ESATTO 3" focuser or ARCO 3" rotator, which have an M81 × 1 front thread. The integrated stop ring allows you to precisely set the adapter's screw-in depth and lock it in the selected position, facilitating back-focus control and orientation of the attached device.

Key Features

• thread conversion: input M81 × 1 (ESATTO 3" / ARCO 3") → output M65 × 1
• stop ring – precise position adjustment and secure adapter lock
• full 65mm internal diameter – no vignetting for full frame sensors
• CNC milled 6061-T6 aluminum, hard anodized – lightweight and rigid construction
• blackened, grooved interior - effective reduction of reflections, better contrast

Set components

• M81 → M65 adapter with stop ring
• Allen screw locking the ring

Technical parameters

• input thread: M81 × 1 (female)
• output thread: M65 × 1 (male)
• material: aluminum 6061-T6, black anodized
• compatibility: ESATTO 3" lift, ARCO 3" rotator, accessories with M65 × 1 thread
• EAN: 8059020774295
• manufacturer: PrimaLuceLab – Italy

PL3600350 is a convenient solution wherever it is necessary to connect a corrector, reducer or other accessory with M65 thread to the wide ESATTO 3" focuser or ARCO 3" rotator, while maintaining full aperture and easy back-focus adjustment.