Take the model 3720! It's a nice improvement over the 3700/3710. The transmission from the rotor to the shaft is belt-driven, when hitting stones and pins, the shaft scrolls and does not break the rotor. Also, for motor insurance, the knife holder sleeve is made of plastic, sold everywhere and costs a penny. Knife and other spare parts are also available. There are no complaints about the mower at all, everything is convenient and ergonomic. The only thing - I think, I will strengthen the handle by which to carry it. I'm a powerful guy, I bent it a little. Empty the container for collecting grass in time, do not mow wet (sticky) - and you will be happy!