Sit on the floor with the legs straight forward and together and the trunk as upright as possible. Start with a pair of kettlebells at the shoulders.
 
Press overhead while rotating the palms to face forward at the top and lock out the full overhead position forcefully as you would with a barbell. Return the kettlebells back to the starting position under control.
 
Purpose
The Z-press position puts more demand on postural strength and control. The kettlebell press is a shoulder and tricep exercise. Because of the way the kettlebells are held, it allows a pressing motion more similar to a barbell press and through a greater range of motion, so is arguably more appropriate than the dumbbell press for weightlifting.
 
Programming
Generally sets of 6-15 are appropriate.