Visual-studio – Visual Studio Wcf Test Client – entering an Int array

I've found the Visual Studio WCF test client quite useful when it comes to a quick test of my WCF service.
This is the test client found in this location relative to your Visual Studio install directory:

\Common7\IDE\WcfTestClient.exe

I have a few service calls that require a parameter of type System.Int32[]
I can't seem to figure out what values to enter against for this parameter as i keep receiving the error

'[value entered]' is not a valid value for this type

Trying to enter the value 27 i have tried the following, but all fails

27
{ 27 }
new System.Int32[] { 27 }

Can anyone please help with how to do this