What is the Content-Type field value in rest client for Zipped files

I am testing in Google Chrome REST CLIENT. Please let me know what we need to pass to Content-Type when our attachment in ZIP File.

When we pass

"application/octet-stream" for Content-Type field in rest client.

and see in debugging mode

In Method: /IWBEP/IF_MGW_APPL_SRV_RUNTIME~CREATE_STREAM, in parameter ==> is_media_resource-mime_type we are getting value as "multipart/form-data", Due to this reason I am not able to see the actual Zip File XSTRING value.

reffred: http://stackoverflow.com/questions/856013/mime-type-for-zip-file-in-google-chrome)

In my Gateway client when I am passing as below screen shot and I am able to see correct Zip File XSTRING value In Method: /IWBEP/IF_MGW_APPL_SRV_RUNTIME~CREATE_STREAM

Please help.

Below are the F4 values I see in Content-Type field:

1. multipart-form-dataapplication
2. x-www-form-urlencodedapplication
3. jsonapplication
4. xmlapplication
5. base64application
6. octet-streamtext
7. plaintext
8. csstext
9. htmlapplication
10. javascript

Thanks,

Madhu M V