Male thread - M42X0.75; Female thread - M42X0.75; eliminates a range of focusing problems
The extension tube has a T2 interior thread and a T2 exterior thread for elegantly solving spacing problems in astrophotography.
Use this extension tube for getting the correct image scale or the exact spacing required for reducers or field flatteners
Precision Thread Conversion: This telescope adapter is designed with external threads at both ends of M42×0.75 T/T2 male thread and internal thread of M42×0.75 T/T2 female thread
Anodized Aluminum Material: All metal construction, which significantly extends service life of product; Lightweight aluminum construction effectively minimizes load on telescope accessories, making it well-suited for long time astronomical observation