http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?sitex=10026:22372:US&item=4206

Still allowed by code. There are many two wire systems out there. Like my house.

Interesting .... while my home had those until recently, the two-prong receps carried / ordered by the parts house had the more 'conventional' pair of slots.

Naturally, my home is now all three-prong receptacles. I just knew that someday I'd find a good use for GFCI's and Wiremold extension boxes

These are the ones with the "T" slot on both sides
I am not sure why you would need that or how you keep the 240v plugs out.

Yup .... my place HAD the 'T' slots.

I think that was the point of the design - to accept as many different plugs as possible. Remember, they come from a time when there was no NEMA, let alone standard plug patterns. I've even seen a variation that was not polarized.

Yah, it makes me wonder why they are still making something like that.[with the tandem slots] What is the use? 240 plugs? New ones have a grounding prong. You'll either need a side cutter or a hammer to make that fit... I don't think I have seen an old 2 prong tandem plug for sale. I have seen some old 2 prong plugs with one blade tandem and the other straight, and it was rated 15 A 125 V. It wasn't terribly old either.I wonder if this receptacle is dual rated like the old ones were, something like 15 A 125 V and 10 A 250 V. Note: Non UL. it says. Perhaps it is manufactured for other countries such as Mexico or some South American countries that do not have listing requirements?

I seen this pic posted on another board, and thought (Or hoped) someone photoshopped it...

Leviton still has stock.

Possibly for people who care about the aesthetic of having matching outlets, rather than functionality/safety?

Interesting how the slots are not centered (vertically) on each outlet, but are in the same position as they would be for a grounding-type receptacle. I presume that the insides are the same as a 5-15/5-20/6-15/6-20 but they just use a different front.

I agree, Paul. I'm sure that the insides are the same as a standard 5320 grounding receptacle with a different face. The original ones were centered for sure.