How about those tealights in metal cups?

I used to buy a bag of 100 tealights. Until I started wondering what to do with the metal cups after the candle inside it has been used up. The thing is, you can’t use just one tealight – the light it provides is just not enough. So what are the options out there – eco-friendly tealights, if you will – to replace these tealights in metal cups? If anyone knows, please leave a comment or send an e-mail.

Image is from this Wikipedia page.