Orion 7377 298mm ID Telescope Tube Rings<div style="text-align: left;"><strong>[Product Information]</strong><ul><li id="replacementPartsFitmentBullet" class="aok-hidden" data-doesntfitmessage="We're not sure this item fits your " data-fitsmessage="This fits your "><span class="a-list-item"><span id="replacementPartsFitmentBulletInner"><a href="#" class="a-link-normal hsx-rpp-fitment-focus">Enter your model number</a>to make sure this fits.</span></span></li><li><span class="a-list-item"> Set of two cast-aluminum telescope tube rings with quick-release， hinged clamp knobs and felt lining </span></li><li><span class="a-list-item"> Use these tube rings to attach an Orion 254mm f/4.7 reflector telescope optical tube assembly to a mount or dovetail mounting plate </span></li><li><span class="a-list-item"> One tube ring has 1/4"-20 piggyback camera adapter; the other has threaded 1/4"-20 hole </span></li><li><span class="a-list-item"> For use with 10" (254mm) f/4.7 reflector optical tube assembly. Not compatible with Orion 10" f/3.9 Newtonian Astrograph Reflector. See compatibility table below. </span></li><li><span class="a-list-item"> Mounting bolts and washers are included </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/41JVBGOCYML.jpg" noproxy>