For Very Advanced Male Trainers
The 40kg sized kettlebell is a serious kettlebell for serious trainers.
Only after you have put in many hours and thousands of reps perfecting your technique and building a solid base of strength and fitness with the 24kg & 32kg kettlebells should you move onto the 40kg.
However, strict pressing of the 40kg is a great achievement if they are are willing to put in the work. If you only weigh around 80kg then a strict 1/2 body weight press is truly a great achievement.
For those trainers unable to press the 40kg kettlebell but who are looking to progress in the coming months, they should use the 32kg and then 40kg for swings and get ups to build an overall strength base to help prepare the trainer to press the 40kg in the future.