The TooHR 3 bar has the same diameter as a TSProf K03/Pioneer/Kadet bar, so any of those clamps will work without an adapter.
If you wanted to use other clamps, like Hapstone, then you'd also need a Gritomatic "GearConnect" adapter for it. Link below is an example of one of the adapters to use Hapstone clamps on a TooHR 3 bar.
GearConnect adapter to use Hapstone clamps of standard size on TSProf knife sharpener (K03 or Kadet) in K03 Profile.Read more about GearConnect for TSProf.Attention! GearConnect adapters use 4 mm hex sockets, no tools included. All adapters are sold in singles, never in pairs. GEARCONNECT is the...
www.gritomatic.com