Go to https://secure.sentinelagent.com/Account/NetworkInstall/

The Network Installation function may be used to install SentinelAgent on multiple machines on your network.  Clicking on [Generate Install Key] will create a unique hash key for your account, allowing you to deploy the MSI package with any tool you choose.  Simply download the agent once and then deploy following the below syntax: 

msiexec /i Sentinel.Agent.Setup.Release.vX.X.X.X.msi /quiet InstallKey=