I've heard everything everyone said before me. lol Skin oils, alcohol break down the tubing...make it dried and cracked. I was told when I bought mine years ago that I should use armor all once a month, etc. I actually have two Litmann's (one has sentimental value and I don't like bringing it to work, I've had one stolem before), so when I had my usual one refurbished I used my "back up". I've had one scope for 10 years and one for 7 years, and I've only sent each one in to be refurbished once. I don't use the armor all, but I don't hang it on my neck or use alcohol on the tubing, they've been fine. Send it in to 3M...I think it cost me about $60 or so...and they'll replace the tubing and refurbish the scope. Good luck!