The D16-C is designed for rotary work in general dental surgery, where a contra angle brings the working end to surfaces a straight piece cannot reach. The head is slanted away from the body and holds a recess, so the bur is carried at an angle to the barrel. That layout is why a contra angle is chosen for surfaces on the sides and back of the mouth.
Restorative rooms and hospital clinics keep contra angles ready across many short appointments in a day. The D16-C has a slim profile and a plain metal finish, and the blue band midway along the body gives the team a quick visual cue on the tray. The SOCO emblem on the side lets the team read the maker's name without turning the piece over. At the end of a session, each handpiece goes back to its place on the tray, and the band makes a missing piece easy to notice.
The range title gives a1:1 ratio, so the working end turns at the speed the drive delivers. External channel is the other phrase in the title. Neither phrase comes with further detail in this model's description, and a team that wants more can request it through Medigear.
Practice managers and dental assistants handle the ordering side. One code, D16-C, names the handpiece. A practice that equips several rooms uses one code for all of them, which keeps reorders to a single line and keeps trays uniform from one room to the next.