Whatever that means.
Still, in lieu of other volunteers, this pair make great subjects for playing around with some old camera gear. Legacy lenses that is, those that have been used on film cameras and then tucked away and forgotten after digital came along. Some of those are good glass too. Some, really good. With some cheap adapters they can be attached to your DSLR and put to great use.
The above Miranda 24 mm f/ 2.8 MC Macro Lens is a good example of this. Probably around 30-40 years old, but built to last, this is a nice fit on my Sony. There's some signs of fungus creeping in around the edges and, if I was any way inclined I could strip it down and try to clean it up a bit. I'm not, and it doesn't show up in any of the shots I've taken (that I can see anyhow). It's all manual focus, but the extras built into the Sony (digital zoom, focus peaking, in body stabilsation) make it pretty quick to operate after a bit of practise. All the rings click in to place clean and firm and, even with the adapter, it's not too bulky on the front of a mirrorless system.
You used to be able to pick these up really cheap, when people though they didn't have much function beyond their original application, but prices have been gradually going up as more realise how much bang for your buck you can get with some of them. Worth a dig around the attics and car boot sales though.
More pin-sharp mutt mug-shots below...