We've been manufacturing solid state relays (SSRs) for more than 40 years now.

In fact, that's how Opto 22 started: our founders discovered a better way to build SSRs.

So of course we want you to use SSRs. (And choose Opto's guaranteed-for-life models!) 

SSRs have largely replaced the older electromechanical relays (EMRs) of decades ago, thanks to their many advantages.

But for a few applications, you may want to consider an EMR.

Take a look at our SSR vs. EMR blog post and check your knowledge. Which should you use?