These are not cordless gas cylinder straightners but the base unit plugs into the wall and you can use the straightening plates away from the base. I have them and they're great.
Currently £35 ish at Tesco direct
Sorry don't know how to add a picture.
Up to 230C salon temperature performance.
1 in tourmaline-ceramic plates for a smooth shiny finish.
Advanced Ceramics - ready to use in 30 seconds with ultra fast heat recovery.
Cord or cordless use straightener for total styling freedom and convenience at home.
Up to 4 mins cordless use.
Returns to heat in seconds when returned to power base.
3m lock-in cord for total flexibility.
5 temperature settings for all hair types.
Power base for cordless use.
3 year manufacturer's guarantee.