Profile: Parallax Instruments, Inc. specializes in offering telescope tube mounting rings. Our products include telescopes, equatorial mounts, standard tube rings & rotating rings and aluminum telescope tubing. Our reflecting telescopes are available in apertures of 10, 12.5, 14.5 and 16 inches. We build telescopes as fast as F/4, and as slow as our high magnification planetary F/10. All telescopes are made of aluminum and stainless steel for corrosion resistance. They also feature mirror cooling fans, tube baffling systems, low profile baffled focusers & optics to produce stunning planetary and deep sky images.