Anyone can answer me !!

which of these machine is suitable for coarse hair ? and which of them is suitable for fine hair ?

GentleYag and Gentlelase

my skin type is IV

do you mean there is no difference between GentleYag and Gentlelase except for ski type ?

my doctor told me that Gentleyag is for fine hair !!!

GentleYAG is an Nd:YAG laser.
GentleLASE is an alexandrite laser.

Please check out the FAQ.

All lasers only work on coarse dark hair, as mentioned. Fine and light hairs require electrolysis.

thanks for your reply

what is the best GentleYAG OR GentleLASE ?

Again, it depends on your skin type. As a type IV, GentleYAG is probably a better option for you. If the hair is not coarse and dark, no laser will be effective.

No laser works on fine hair. Different types of lasers are made for different skin types, i.e. it only matters how dark your skin is. The hair needs to be coarse regardless of type of laser for it to work.

Please read the FAQs below.