Taken from the Meguiers website:
Endurance Tyre Protectant Gel
Finally, a tyre protectant that lasts weeks, not days… even after rain and washing.
Endurance is a significant advancement in tyre protectant technology, providing a rich, dark "like new" look for weeks longer than you expect with ordinary protectants.
Endurance is a concentrated gel that saves you time and money by eliminating overspray, runs, drips, spotted driveways, messy cleanup and stained towels.By lasting longer, it also saves you money because it requires fewer applications.
An added bonus is that Endurance contains revolutionary antiozonants and protective polymers that help prevent browning from environmental elements.
This keeps your tyres looking true black.
No runs, overspray or stained driveways
Comes with special applicator
Available in 'natural look' and high gloss finishes
Now in 16oz/473ml size for even better value
It doesn't state anywhere in there about silicon, so I guess they must of had that previously but has now removed it from the contents.
I'll probably go and buy a bottle and compare it with what i got and see how we go.