Northern Tool offers the Ironton 131-Piece Rotary Tool Kit, model no. 46136, for $37.99 with free shipping. That's the lowest total price we could find by $5, although we saw it for $5 less in October. This 160-watt variable speed rotary tool operates at 8,000 to 35,000 rpm and includes wire brushes, sanding pads, felt wheels, grinding stones, and drilling accessories.