The HIOSSEN Crestal Approach Sinus-Kit (CAS-KIT) is specifically designed to easily and safely lift the membrane in the maxillary sinus by method of crestal approach. Unique design of the CAS Drill is the key feature of the CAS Kit. With its unique drill shape, it has enhanced the convenience and the safety of crestal approach sinus surgery by creating conical shaped bone chip to safely lift membrane. CAS Drill also provides precision drilling, smooth and stable insertion, easy path correction, and septum surgery.