What are 1.25G SFP used for? What kind of company buys them?

[aneqniapmn]

Below is a link to the products I'm referring to. What are they used for ( in detail & in layman terms ) ? What kind of company buys them ? How can I approach such companies ?
Allray Inc.
Atop Corporation

 

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SFP is a modular slot that lets you plug in different kinds of medium so you arent limited to ethernet only. it allows you to have multiple mediums on the same device so you wont need modems. It means less plugs, power use and less space as well.