This pack of 5 2" caps allows you to protect your 2" eyepieces. They fit on the barrel end of the eyepiece that you insert into the focuser. They are made of soft yellow plastic so they are quick to put on and take off, and easy to see in the dark. Fits all brands of eyepieces such as Televue, Takahashi, Meade, Orion, Vixen etc. Because they are made of soft plastic the eyepiece cannot be stood on end.