It is the OV-25. The "L-250" and "L-150" names are fake. Yep the OVZ, -Y, -H, -F, and -X are all still being made. OVD, OVG, and OVL were dropped a few years back.

These are by far my favorite "medium" cobraheads. The 4th-generation OV-15 is also one of my favorite small sizes.

I guess I'm going to have to changing title name. By the way, is this the fourth generation of the OV-25? Just saying, I remember that there were generations of the OV-25s.

It is the 4th generation. First was the flatbottom, second was the single door between 1964 and 1970, and third generation from 1970 to 1978. I have all of them in my personal collection.

Very recently I acquired a Westinghouse OV-15 that's a factory 250w HPS unit. It's 1978 vintage, still got the good ol' 1970-78 Silverliner design. I also have a 1977 OV-15 175w MV.

Nice! I'll try to see if I can get a hold of one of these 4th generation OV-25s.

@Silverliner14B, are the slipfitter rods 3/8" or 1/2"?

I have a 4th generation OV-15 from 1979 with the 1/2" threaded rods and another one which I assume is early 80s that has 3/8" carriage bolts through the top housing The 1/2" one had a 200W HPS ballast (either 208 or 480V single tap; forget which) that I converted to 85W induction and the 3/8" one is 100W MV, 120V. Both are pre-Crouse-Hinds versions but the info is worn off the paper labels. I went by the capacitor on the 200W HPS one for a date. The 100W MV one has no capacitor. I'll have to inspect the ballast for a date code if that label is readable.

My OV-15 is also from 1979 and has the 1/2 threaded rods. Did you get yours from that seller in Michigan who had them a while ago?

Yep got it on ebay for like $35. Makes sense that we got the same light. I had to add a PC socket to it since it didn't have one originally.

I'm seeing the dividing line between the third and fourth generation models, LOL. I'll need to check the diameter of the rods in mine but they're the threaded rods. My 1977 OV15 is also the same.

No need to check the rods, check the NUTS. If you have to use a 9/16" socket, then you have 3/8" rods. 3/4" socket means 1/2" rods.

I'll need to check next time. I'll also take good pics to post here.

The nuts would be 9/16" for the 1/2" rods and 1/2" for the 3/8" rods. 9/16 and 1/2 are the only size sockets you'll ever need for a cobrahead slipfitter.

Actually, for the 1/2 size rod you need a 3/4 size socket. @streetlight98

I've never seen a cobrahead use anything other than a 1/2" or 9/16" socket. One of my 4th gen OV-15s uses 1/2" nuts and the other uses 9/16" nuts. They must use 5/16" and 3/8" diameter bolts. All GE lights require a 9/16" socket for the slipfitter but Westy seems to have used both 1/2" and 9/16". Much more standardization on GE's part over the years.

Westie used 3/4" not 1/2" Joslyn used the smaller 1/2" size bolts.

My OV-10IB, OV-25 remote ballast, and RMA NEMA head all use 1/2" bolts. I guess only the earlier and smaller lights Westy made used the 1/2" head bolts?

Hey guys, i'll try to see if I can get a 4th gen. OV-25, but they're HPS, not MV.

The original OV25 had 3/4" hex head cap screws, as did the 2nd generation. Third generation went to the 1/2" rod and 3/4" nut combo.