Delta 40-694 20″ variable speed scroll saw features: on/off switch, electronic variable speed dial, flexible dust blower and blade-tensioning lever are all conveniently located up front on the arm for easy accessibility tool-free blade clamp allows for quick, easy blade changes in seconds single lever, tool-free blade tensioning allows for quickly adjusting the blade to the proper tension which maximizes blade life and accuracy large, cast-iron table provides excellent material support and bevels 0 – 45 left and right tool free blade clamp allows quick and easy blade changes in seconds single lever, tool free tensioner quickly tensions blade for accuracy and maximum blade life on tool blade storage