Slimline holderes have a smaller nose diameter. Perfect for finish passes where small nose diameter is needed. Techniks ShrinkFIT holders have T.I.R. of 0.0001″ or better. Balanced to 25,000 RPM at G2.5 tolerance. Ideal for high speed or high torque machining applications. Each holder is Techniks Certified for accuracy and balance and comes with an individual lab report. Tool life is extended by as much as 700%, stretching your budget farther. Coolant-thru spindle, comes with coolant-thru set screw installed.