VW Bus Reverse Light - Double Bulb - 67-71 - 1967

This tail light housing will allow you to run dual bulbs on a VW Bus reverse light (67-71 style)

It's useful for doubling your reverse light output with two bulbs, or for creating a combination turn signal (amber) and reverse light (white) in the single housing...which will let you turn the red oval taillights into brake lights only (and not do double duty as turn signals)....or, my favorite, mounting a freaking insanely bright headlight bulb as your reverse light (giving you around 10X the output of normal..heh) and also using it as a turn signal.  You could also be crazy and mount two headlight bulbs in each housing, lol.   If you wire the reverse 12V wire to your battery instead of having it be switched off ignition, it can make a nice camping "work light."

You can mount two of these sockets for 2 x single filament tail light bulbs
https://www.amazon.com/gp/product/B0139WX0BQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

you can retain the sockets with a single screw and will see that the flanges are offset to accommodate the thickness of the  socket stackings

something like this under the  screw will provide a ground terminal 
https://www.amazon.com/Quick-Cable-169137-025-Non-Insulated-Solderless/dp/B01MY5JC82/
or 
https://www.amazon.com/Quick-Cable-169138-025-Non-Insulated-Solderless/dp/B01MR3BILR/
(the double one is useful for adding a ground wire terminal for use with a headlight bulb as reverse, see below)

alternatively, you can get creative and mount something like a LED headlight bulb directly into the flange instead of a bulb holder...and then use a single bulb holder (e.g. with a 1156 amber bulb) in the other bulb hole and have a rear facing headlight for reverse ("backup lights of the Gods!"), and also have the housing act as an amber dedicated turn signal like a new car (or late Bay window bus).   

For example, here's a super high power H4 headlight .. simply wrapped in self-fusing silicone tape and inserted into the housing directly with a friction fit, very similar to how many high power LED tail light retrofits (with external drivers) are fit to brake lights.
https://lh3.googleusercontent.com/gZ9wOdCZVhKbBpULp3oaYuDGzvB1azYrR4DnwKrY90MRIe4FR2rcbO4x8XnGJ8hMZj7BozOPPtOkw_djgj54WiHPwrSVwJtqnMqjI9PE3YmrfYkbhqZkuGbjOtbE5hnt8nK3e7v2QPg=w2400 

If you go the route of using the reverse housing as a reverse light AND a dedicated turn signal.....  on a Bay window Bus , separating your turn signal from your brake lights is easy (like the way they do in Europe).  Take the terminal 54  wire (typically yellow or black/red and in the middle) on your Hazard switch and disconnect it from the switch...and run  that one wire to the rear tail lights - and splt it and feed that to your brake lights...connect it to the high filament to the 1157 bulb (not the running light)...and then take the existing wires that were on  the brake lights before and move them to the amber turn signals.  Done. 

Pretty easy.  And now you'll have modern turn signals and brakes...much safer for keeping distracted drivers behind you from rear ending you.

Either way, these are great....super bright reverse lights or modern separate brake/turn signals (sort of like Euro bus style, but cooler).

You can use a bolt and a nut to retain them, like the EMPI reverse lights...but they are designed to use one of these brass nut heat inserts...that you basically push into the hole with a soldering iron and wait for it to melt into place.
https://www.amazon.com/gp/product/B0B46YBNV4/

NOTE: this is a single housing , order a quantity of 2 for a complete pair.