Gut-a-Like Deluxe Double Bass Strings

I have always used guts for my playing however, they dont last as long Id like. they need oiling and are regularly going out of tune due to temperature or humidty changes.
I tried a set a year ago and was converted. these strings sound very like gut but stay in tune and because they are made from a more stable material will last a long time. My first set are still going strong. Not cheap....but guts arn't either.