Toe kick peninsula

[GoldDigger]

I am betting it has to do with 300.15(E) or (H)

I won't bet against you.
(E) looks very good, while (H) refers us to 334.40 which in turn is limited to exposed wiring (I remember some old plastic surface mount receptacle assemblies that had an opening suitable for surface mounted NM) or to fished concealed wiring in existing construction. So (H) would probably not help the OP.

 

[kwired]

I'm guessing 300.15(E) as well. One of most common items that this applies to is the switches and receptacles often found in mobile and manufactured homes that do not require a separate outlet box. The Sillites device appears to be similar in construction - as in it has an integral enclosure.