The safety button is positioned very unergonomic, it is very difficult to reach with your thumb. It also provides no security for the second hand. In order to work, I have this safety button once Elastoplast stuck in the position "A".
The gap requires about 1 second for closing, which is slow compared to a manual lopper. Calculated over the day, however, the performance is higher as with left and right hand can be used alternately and even muscle and tendon gently. (The manual shears it was in the evening always the verge of a tendonitis)
I have thus worked 2 days in continuous operation. The lopper still work properly. Only the knife had to be sharpened.
All in all a good buy.
This lopper I can recommend.