can anyone recommend a good rubber preservative?

I would like to know if a readily available,and easily obtained product for "preserving" rubber,like speaker surrounds or the rubber lip,on my vacuum turntable can be had.I don't believe something containing silicones,like Armorall is good,in the long run.
Anyone know of such a product,and where it can be found?
Thanks so much.
There's a product called Rubber Renue from MG Chemicals that comes highly recommended by UHF Magazine. Here's the page it's on :
As noted in another thread, there are a wide variety of natural and synthetic rubber products on the market. A compound that helps preserve one could potentially damage another or change its operating characteristics in the case of a driver surround.

Unless approved by the manufacturer, you'd be using a preservative at your own risk. It might work perfectly for someone else and horridly for you (or vice versa.) While it is certainly tempting to extend the life of your equipment, you are shooting blind unless you have some specific direction from the people who made the product.
a fresh box of condoms is like, what, six bucks? Just splurge.
But buy the box before you splurge.
That was the best laugh I've had in some time on this forum - thanks Kublakhan and Tarando!