• Front side - M26x0.5 female thread
• Rear side - M28.5x0.6 male thread
• 3mm wide retaining ring included

Machined from high quality aluminium alloy.

This adapter allows using filters in 25mm or 25.4mm (1 inch) round frame on 1.25 inch telescope accessories/eyepieces.

Suitable filter thickness is up to 5mm.

This is an improved version with the retaining ring. It is purposed for bare glass filters without a metal frame. If your filters have frames, you may use a more simple holder with set screws.

This clamp also fits Shelyak’s replacement slits for its ALPY600 spectrometers, which are exactly 25mm OD. This allows to incorporate any of Shelyak’s ALPY-compatible slits into some customized spectrometer designs.