I have used these lids for 2 years now and within the last 6 months, they no longer fit snug like they used too. If you pick the candle up by the lid, they will slip right off. I emailed Candle Science about it and mentioned it to the rep. Today I notice they under the description that they have changed suppliers so maybe that's why they no longer fit snug anymore. It's not worth the risk of a broken candle from picking it up by the lid and it falling.
I've started taping the lids on the jars recently so that I can use what I have, but when this box runs out I have decided to just find another jar.