The "light tube" or what ever they call the plastic insert fell out and was lost at the range. I looked all over and couldn't find a replacement. I called Sig and they said the front sight needed to be replaced - and it was covered under the warranty!
However, I had to pay $27 for shipping. They sent me a Fedex label and 5 days later I got my slide back with a new front sight. I can't complain about the service. The job was done well done with no marks and the turn around was prompt.
But still $27 to fix a problem that could be resolved with a tiny piece of plastic seems costly. Is there a source for these tubes? My Hiviz sights come with replaceable tubes but they don't fit this sight.

If you check at Brownells, they have several different replacement rods for sale. You need to measure the diameter of your rod then you can order a replacement.

Thanks. I don't know why I didn't think of Brownells. I just ordered from them last week.