kitchen waste

I can’t work out which compression elbow has been used. I’ve only removed the sink waste elbow, but it revealed a 45mm pipe - 1 3/4 inch-ish I guess. All I I can find, though, are McAlpine ISO 1 1/4”, 1 1/2” and 2” elbows. I’m a bit stumped, to be honest. Any help would be appreciated. Thanks.

hi, I've Lived in my house for almost a 6 months now and one thing that's been bothering me is the slow draining sink. I've tried a few different chemicals from amazon and the usual drain unblocking products from the supermarket, nothing was working. I took the pipes apart from underneath the...