It's an LED headlight similar in design to the Honda Hornet light used on my black '92. The wiring connector plugs directly into the bike's H4 plug.
This headlight needs a housing that supports an H6024 style sealed headlight (like you used to buy at the department store for your 70's car). I found several that look like they will work. Two, specifically, are made by EMGO:
EMGO 66-65010: This is a replica of the Kawasaki headlights used on the 70's model KZ's. It secures the headlight similarly to how a car would, using two plates. It is adjustable left-to-right.
EMGO 66-65068: This is a replica of a Lucas light as used on many early Triumphs, BSA's and Norton's. It secures the headlight using W clips, directly to the retaining ring. There is no adjustability, left to right.
I chose the EMGO 66-65010 mainly for the way it mounts the headlight. Given the weight of the Trucklite headlight, I thought this was the better approach. I do like the looks of the 65058 much better. If the 65010 doesn't work out, I'll order the latter. Note that both shells are under $40.