Drainage help required

[wolfracesonic]

Does anyone know what type of bottle gully this is. Trying to help a friend stopping drain smells entering his house. There is a bottle type gully set in concrete as normal, with a hole in it, as normal to let water discharge to the underground drainage. The thing in the picture has a soft rubber seal around it’s opening that I think should compress against the gully opening creating an air tight seal, however it’s just sat in the gully loose allowing odours to escape.
There is a screw on the top of it but I can’t see anywhere on the rim of the gully it fastens into.
I’ve not seen this type before, I wondered if anyone knows what it’s called so I can do a bit of research; the property is mid 80s, I’m wondering if it’s a proprietary system that’s no longer available, thanks.