The string trimmer handle (ST1502S) is very uncomfortable for me.
The manual does not tell you how to orient the handle around the shaft. The drawing seems to suggest installing it with the "V" part of the handle in the 12:00 position. However, that "V" curvature is too tight for my hand. It is very uncomfortable to hold the trimmer with the handle installed in this orientation since most of the weight of the trimmer is concentrated at that point when being held.
My recommendation is to open up the "V" so that it doesn't hurt my hand/isn't uncomfortable when holding the trimmer.
Related, if you are not going to redesign the handle, the manual should be revised to describe the recommended orientation so that everyone with large hands can comfortably hold/support the trimmer at the flatter part of the handle. It is not obvious (to me, a right-handed user) whether it is better to point the handle at 9:00 or at 3:00 (or somewhere in between).