easy to install: the telescope tube mounting rings are easy to install and do not require complex steps to complete the installation telescope accessories: the telescope tube rings are suitable for professionals and astronomy enthusiasts, fixed main mirror and equatorial instrument, telescope accessories package includes: you will receive 1 pair telescope tube mounting rings material: the telescope tube rings are made of metal material, which is reliable in quality, sturdy, and has long service time high performance: professional manufacturing telescope tube rings, which are compact and portable, is suitable for 80dx