America screw threads are based on TPI (threads per inch). So if screw is16tpi, turning ring 16 times gives exactly 1 inch. So the ring design is a superior design for people using inches.screw design and ring around
In metric countries, their screw thread is based on x.y mm per turn. So Bosch and Makita etc cannot use the ring height adjustment design as used by many American designed routers.
Bosch uses 1.6mm threads screw for their presumably "Amercan models". Turn the knob 16 times and you get 25.6mm which is NOT exactly 1" (25.4mm). Turn the know twice won't give you 1/8". It is NOT precise.
The dust chutes design of the Dewalt. routers are also superior to Bosch.
(many years ago, I was warned by a moderator of this forum to never criticise Bosch. So stayed away for years).