Curved Bars and Belly Bars - Internal Thread
Internally threaded straight bars that measure either 1.2mm or 1.6mm gauge externally. These bars accept externally threaded attachments appropriate to their gauge. For information, externally threaded attachments for 1.6mm shafts have 1.2mm threads. Externally threaded attachments for 1.2mm shafts have 0.9mm threads.
NB - rotate your device for full filters