Check the listing for details. Celestron C11 W/ Hyperstar Tri-Bahtinov Cap mask Split, connects on telescope. Condition: New. Listed at 26.99 USD. NEW TRI-BAHTINOV MASK VERSION! BY SPENCER-3D Celestron C11 W/ Hyperstar Tri Bahtinov Cap mask, Split with two sections, Now upgraded and thicker mask to have more strength. Would also work with regular C11 with no Hyperstar. Celestron C11 or HD 11 Inch , this version is meant foC11 with Hyperstar . It connects on end of telescope and comes in a split design to put on and off very easily. measurements before purchasing for your telescope. . This is meant for Celestron c11 or edge HD 11 with Starzona Hyperstar . , if buying for regular version it will have some space in middle diameter hole of cap. Special design to split apart. More options will be available for the C11 hopefully soon. C11 bahtinov masks also available just ask. Condition is New. Shipped with USPS First Class. Software Designed and tested. Works great with these and similar models. 3d printed and designed by Spencer 3d. As always fast USPS SHIPPING. 2 TO 3 DAY SHIPPING. BLACK . Other colors and types available just ask. If need a particular size message me,or if have questions. SHIPPING CHARGES ARE CHANGING SLOWLY ON ALL OF MY ITEMS i MAKE AND SELL. DUE TO INCREASE OF SHIPPING CHARGES AND SHIPPING SUPPLIES, MANY OF THE ITEMS THAT WAS FREE SHIPPING WILL BE CHANGING OVER SLOWLY TO SHIPPING THAT IS CHARGED TO THE BUYER. bUT THIS WILL ALSO MEAN CHEAPER PRICES ON THE ITEMS THEMSELVES, AND MORE SHIPPING OPTIONS WITH FASTER SHIPPING OPTIONS. ALSO MANY ITEMS TAHT WERE NOT BEFORE AVAILABLE FOR INTERNATIONAL SHIPPING WILL NOW BE AVAILABLE FOR INTERNATIONAL SHIPPING.