There were several reasons we chose SchellVac. After we visited with Alex and Sergej, we felt that they knew their stuff. They were very knowledgeable of there work and products and very willing to incorporate our ideas into the unit we had built. The unit has worked very well since purchased. Very dependable. Their staff has been very accommodating. I would recommend SchellVac in a heartbeat. In fact, I already have, I believe A1 Sewage is going ahead with a unit. We will most definitely use them again.