Moved from Globular Springtails.

Indeed.
Wrt setae. Each seta is sensory. It senses the movement of the setal shaft. Common seta can move only in one direction. They can move backwards and forwards in one plane, orthogonal at the cuticula. Some setae can move in all directions and they sense the direction of the movement (like a joy-stick). These are called 'bothriotricha'. Often they are placed in a cuticular pit. See https://www.collembola.org/images/france/garcelon/2020/Tomocerus-minor-20200319-Philippe-Garcelon-France.gif
Other setae have a shaft with pores by which chemicals can enter and sensed by the nerve that is in the shaft. Most found on antennae.
Thick setae are called spines. They do not move. There function is to protect body areas.
Setae are classified by their size in microsetae, mesosetae and macrosetae (small, middle and large). They are also classified by the shape of the setal shaft : e.g. acuminate (pointed), clavate (knobbed), bifurcate, serrated, feathered, etc
The distribution of setae on the body is important in species diagnoses (chaetotaxy). In other words, the setae on the body are mapped and the map defines species.
Each seta on the body of Collembola have been designated a name. That is used in species identifications. As in "if seta AA is present on the 4th abdomen, then it is that species, if absent then it is this species".