The RSB-SOV-C13 has the widest aperture for tools made from round section at 1/2" and is perfectly aligned to take 3/8" bowl gouges and fingernail bowl gouges, the 1/2" spindle gouge, fingernail spindle gouge and the long and strong spindle gouge as well as the TurnMaster.
The Spiralling System and Texturing Tool also use this collet.