| These 95mm internal diameter Parallax split tube rings fit the Takahashi FS-78 and Sky 90/Sky 90 II refractor optical tubes. The rings are made of die-cast aluminum and are hinged for easy telescope installation and removal. Their hinges and no-tool knobs and hardware are made of stainless steel for long life. The rings are finished in subtly-flecked dark gun metal gray paint and are felt lined.
Three 1/4"-20 thread mounting holes are drilled and tapped in the flat boss on the bottom of each ring for installing the ring on your mount or mount dovetail plate. One hole is drilled on the centerline of each ring and is flanked by two identical holes on 37mm centers. A similar hole pattern is drilled and tapped into the top boss of each ring to allow the attachment of an accessory dovetail plate or piggyback ball-head camera mount.
The 1/4"-20 center holes are used to install the rings on the narrow dovetail plate used on Celestron Advanced Series, Meade LXD-75, Vixen Great Polaris or Sphinx, and similar mounts. While these mounts can hold the weight of the optical tube, the rings, and the added weight of other basic visual accessories, be certain that the payload capacity of your mount is sufficient to hold that weight plus the weight of any additional photographic accessories you might want to add.
The center holes can also be used to mount the rings on a wide dovetail plate, such as one of the Losmandy universal dovetail plates (#DUP and #DUPS), that have a series of holes or slots drilled along the centerline of the dovetail.
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