What is this hot water heater anode type???

[CPB]

I have two hot water heaters, and as I was about to tackle replacing the anodes (have owned the house for 3 years and suspect they may never have been changed) I noticed one had a very unusual cap. What should I do?

I've attached both photos (I think, it looks like one may not be uploading from the iPhone) and hopefully it's obvious which is the unusual anode cap.

Thanks!!
CPB

 

[KULTULZ]

The nipple or condo rod is blocked off.

Can you take a few shots of the complete installation(s).

Where is the TPRV mounted in your tank(s)?

 

[Matt30]

It looks like someone removed the anode, installed a dip tube and capped it.

 

[KULTULZ]

It looks like someone removed the anode, installed a dip tube and capped it.

What if???

Somebody simply replaced the hex anode with a combo (for whatever reason) and then capped it not to leak?

But, what worries me, is that the washer is white meaning the TPRV was installed there originally. Where is it now?

I cannot see the RED washer/HOT outlet.