Depending on whether you’re installing into a new home or retrofitting an existing faucet, plumbing regulations will vary by country, state, and municipality
If you are installing on a new construction property, we recommend checking your local codes before choosing a model. Both Hydrants are ASSE and CSA certified, however, some areas may require a built-in vacuum breaker, rather than an external one.
If you are retrofitting aka replacing an existing spigot, you can go with either the V1+ or V2+ model. Both offer the same amount of protection, the V1+ is just a bit easier to install because of the smaller entry hole.