I must have overlooked the sizing chart, but this was too large for my 10 year old.  I have yet to evaluate its strength etc.

Started out with the .5 Red strokemaker paddles at behest of my masters coach....I eventually progressed to the next size up, these #1.0 green paddles.  I am 5'6", 140 female masters doing 3,500 - 4,500 4 x's week and I really needed this bigger paddle; it is doing more to strengthen my stroke then the red and I adjusted easily to the change.  Forces me to get my hips out of the way in order to properly complete my stroke-press with power, thus encouraging side hip thrust (body roll) as one should be swimming (get off that plank! i.e. your stomach)

I use these in training and they are very helpful.  I am a petite master swimmer and they work for me.  My husband also uses the same pair and they work for him too.

These paddles help develop my upper body strenght

Highly recommended by my daughter's swim coach to be used during  practice.