Models Own Eyelash Curlers

I love these eyelash curlers as they make my eyelashes flip right up, but sometimes if you hold them down for too long you can get a harsh line across the eyelashes. I clamp them down for about 5 secs to get the right curl. I know that Shu Umeras curlers are supposed to be the best but I was looking for a cheaper pair. These cost only £6.00 from Boots.