Young receptionist with both hands and feet shackled.

I personally like the simplicity of using shackles while the hands are behind the back, as such restraints are surprisingly effective in reducing one's freedom as well as allowing the use of other types of restraints!
Using only handcuffs around the wrists provides a level of restraint of 1.

Whoa, wait a second!

This type of restraint fastens the left hand to the left foot and the right hand to the right foot while on all fours. With such restraints, the only possible movement is to spread your legs while bent over. The level of restraint is 3.

This is an item that falls into the soft SM category. "Soft SM" is a term used in Japan that refers to having sex with elements of SM (such as using various restraints and blindfolds) but without more extreme parts of SM (typically using ropes or inflincting pain). It generally involves wrapping them around the wrists and ankles.
The best thing about these shackles is that they can be used in any way you like.
This office lady is firmly restrained.

These restraints are designed to be used to keep the legs spread in an M-shape by wrapping them around the thighs and around the neck. The neck and legs have simple cushions to alleviate pain. These restrains have a level of restraint of 5.
It is recommended to use a special chair or a one-person sofa when using these restraints.
The see-through underwear underneath the nudistocking makes it even more erotic. "Nudistocking" means a type of stocking that's meant to be even more transparent than usual stockings.