this variant the hair straightener 30 comprises heatable plates 33 a and 33 b plate 33 a is pivoted about plate pivot 36 positioned at the end of the plate closest to the arm coupling such that plate end 35 a rotates in this arrangement the plates may be biased such that when the plates move from an open to closed position the heatable plates again first abut one another at the mouth end of the hair styler i e at the end of at the heatable plates furthest from the arm coupling which connects the two arms of the hair styler together thus in the closed position the ends of the heatable plates furthest from the arm coupling are closer to one another than the ends of the heatable plates closest to the arm coupling in the variant shown in fig5 hair straightener 40 comprises heatable plates 43 a and 43 b plate 43 a is pivoted about pivot point 46 positioned at the end of the plate furthest away from the arm coupling such that end 44 a rotates in the embodiments described in fig3 a c 4 and 5 it is not necessary for the pivot to be in the same position on both heater plates in variants for example a combination of the arrangements in fig4 and 5 may be used as shown in fig6 in this arrangement one heater plate 63 a is pivoted at an end closest to the arm coupling by pivot 66 a and the other heater plate 63 b is pivoted at the end of the arm by plate pivot 66 b furthest from the arm.