Camera specific bayonet adapter (camera ring) for Canon EOS DSLR with M48x0.75 mm internal thread for astrophotography. 
By using the large thread M48x0.75 mm, the vignetting of e.g. a DSLR full format sensor is effectively avoided. Compared to the small T2 thread M42x0.75, this adapter has a free inner diameter of 47.5 mm. This camera ring is made of matt black anodised aluminium and weighs only 40 grams. The light path (overall length) is 10.0 mm.
FEATURES 
Camera-specific bayonet adapter Canon EOS 
Large female thread M48x0.75 mm 
Free inner diameter of 47,5mm 
No vignetting for full format sensors 
Light path (overall length) is 10.0 mm 
Made of matt black anodized aluminium 
Weight only 40 grams