Extension tube can accommodate eyepieces up to 38mm (1.49 "). After connecting the eyepieces, the distance between the front and rear can be adjusted to zoom in or out to obtain a zoomable image. It is recommended to use eyepieces, which can be fixed in the barrel, so the camera can get higher quality images. (Tip: T2-Ring & eyepiece purchased separately.) Essential accessory for anyone interested in astrophotography. It can be used for SLR camera prime focus photography and eyepiece projection photography.Mirrorless cameras are not suitable for use. Easy-to-use,extendable camera adapter is designed to connect the camera body and telescope together,Eyepieces can be placed inside the extension tube of adapter to increase the detail and clarity of photography. Multiple shooting methods:The eyepiece can be fixed in the front cylinder to achieve a long focal length for small objects, such as photographing the moon crater. Using adapter without eyepieces is equivalent to using the focal length of a telescope,suitable for taking pictures of the entire moon, gas nebula, etc. An essential accessory for telescope photography enthusiasts, this adapter is indispensable for prime focus photography.