I have an idea for a keychain that I want to make it needs to be stretchy and strong. I have never worked with rubber or silicone befor so I am not too familiar with durometer and strength.
Im sure everyone has seen or owns one of the Yellow Lance armstrong bracelets. I am basically looking for a pourable rubber/silicone with the same properties.
I have been looking at smooth-on.com but the main problem is picking a durometer.
I’m guessing that’s its around shore-A 45-50. 40 may be a little too gooey.
If this is your first time with molding, be prepared for mistakes. It’s harder than it looks (but not impossible).
Cool thanks man, I found some silicone hoses online that were 50 so I will probably go with that.
I work with carbon fiber and fiberglass, but this will be my first time making and molding rubber. Should be interesting its a small part too. 
you might want to check out http://www.kulayful.com. i recently just ordered from them and great service it is! Customized silicone bracelets.