EC2 MountPoint Property Type

{
   "Device" : String,
   "VolumeId" : String
}     

This mount point (specified in the Volumes property in the EC2 instance) refers to a named EBS volume, "NewVolume".

"Ec2Instance" : {
   "Type" : "AWS::EC2::Instance",
   "Properties" : {
      "AvailabilityZone" : {
         "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAz" ]
      },
      "SecurityGroups" : [ { "Ref" : "InstanceSecurityGroup" } ],
      "KeyName" : { "Ref" : "KeyName" },
      "ImageId" : {
         "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]
      },
      "Volumes" : [
         { "VolumeId" : { "Ref" : "NewVolume" }, "Device" : "/dev/sdk" }
      ]
   }
},
"NewVolume" : {
   "Type" : "AWS::EC2::Volume",
   "Properties" : {
      "Size" : "100",
      "AvailabilityZone" : {
         "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAz" ]
      }
   }
}