Use the SEARCH bar (top right at the top of the page) and type in ZINC.
You'll see many threads where we've told folk not to worry about Zinc at all, ignore them completely and they'll send the case back to Harlands/CRS.
I'm not sure if the site layout is old but all the info you need is here.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!