A common problem with running the RRS ANVIL-30 bowl with Two Vets tripods is the RRS locking ring does not match up with the Two Vets locking ring. The new Two Vets Anvil-30 Conversion Bowl features a locking ring which is compatible with all Two Vets tripods that have a 75mm bowl opening and fits perfectly. Manufactured from 6061 aluminum, the conversion bowl features a main stud and 4 small locking screws to stop your ANVIL-30 from rotating or shifting up and down. All needed hardware is included and it is proudly made here in the Good Ole USA.