Drill with dead-on accuracy and eliminate "bit wander" by using Replacement Bits for the Rockler Shutter System! Each bit has a self-centering tip that fits perfectly in specific shutter template mounting holes, and a spring-loaded guide that retracts as pressure is applied and the drill bit advances. Features: Eliminates "bit wander", making it possible to drill with dead-on accuracy Self-centering tip fits perfectly in specific shutter template mounting holes Spring-loaded guide retracts as pressure is applied and the drill bit advances 1/4" hex power bit shank Which Replacement Drilling Bit will work with my Louver Template set (sold separately)? 1-1/4" Movable Louver Template Set (49470) uses the 1/4", 3/32", and 3mm bits 2-1/2" Fixed and Movable Louver Template Set (44342) uses the 1/4", 3/32", and 9/64" bits 3-1/2" Fixed and Movable Louver Template Set (47674) uses the 1/4", 3/32", and 9/64" bits