So these are a little odd ... why - because the lower handle is designed to rotate as the secateur opens and closes.  They are designed to be used when all day comfort is needed or if grip strength is compromised.

We have several customers that swear by them... but we've not used them long enough to be able to comment yet.

This model is the ergonomic handle version of the Model 6, which is classed as a Medium hand size secateur.  They can handle cutting material up to a diameter of 20mm.

This is a right handed version.

Aluminium handles with a hardened steel blade.  Generally speaking they require less maintenance than a Japanese style secateur.

Classed as a size "medium" for hands the measure between 17.5 and 20cm from wrist to finger tip.  Sizing guide can be found here.