Home Depot/Lowes/Ace-any hardware
shop. Look for #60, #47, #36 and if you have one that needs a really small o-ring #004. #004 takes patience to get on. More than likely the #60 should do the trick. The name brand (I purchased) of the first
three is Danco. The smaller #004 ones I picked up at oringmonkey.com. Hope this helps in your quest!