Credit: Photo: dotfordot.com
The Hilti TE DRS-M is a unique type of dust collector. The rather large unit attaches to the front of the Hilti TE 7-AC; once fitted, it looks very much like part of the tool.
Other than the telescoping suction head, I didn't notice any difference handling the tool once I started drilling. The rotary hammer's motor powers a small vacuum fan inside the unit via an external mechanical drive. The unit has a telescoping suction head that the bit passes through surrounded by cleaning bristles. As the bit sinks into the hole, the suction head retracts and remains flush against the work surface. The concrete dust is sucked up through the head as it is brought out of the hole by the flutes of the bit and is captured by a filter in the dust receptacle.
This receptacle slips out from the bottom of the unit with the press of a button, making it very easy to empty. It works best with a 4-inch bit; a 6-inch bit extends about an inch past the suction head, rendering the unit useless for the first inch of drilling. The nosepiece retracts far enough to allow a 3-1/2-inch-deep hole with the 4-inch bit, and there is a built-in adjustable depth stop.
I used the TE DRS-M in both straight-down and horizontal drilling, and it worked extremely well, especially horizontally as it prevented any dust from escaping and falling to the floor. The only time a little concrete dust did fall out of the hole was when I pulled the bit out; it doesn't vacuum out the entire hole, it just intercepts the dust being carried out.