I'm not sure what you mean by "mds688". This doesn't appear to be a common abbreviation or term. Could you please provide more context or clarify what you're asking about? Are you referring to:

1. A specific model number?

2. An acronym or abbreviation for something?

3. A code or reference number?

4. Or something else entirely?

If you can give me more information, I'll do my best to help you with whatever you need to know about this term or concept.