Astronomical eyepieces are described by the diameter of the base tube or barrel and come in several standard diameters. This is not to be confused with the focal length of individual eyepieces. The eyepiece diameter for your scope is important to know when purchasing other accessories, too, such as filters.
All LCMs use the standard size for eyepiece barrels today, the 1.25 in. There are many different designs and focal lengths available from many manufacturers. Almost all accessories that fit into focusers are available for 1.25 in. Almost all Celestron telescopes use 1.25 in eyepieces.