Makita 40V Max XGT 1-9/16" AVT Rotary Hammer Kit SDS-MAX (4.0Ah)Makita GRH05M1 40 Volt Max XGT Brushless Cordless 1 9 16 in. AVT Rotary Hammer Kit, AFT, AWS Capable (4. 0Ah) SDS Max The GRH05M1 features Active Feedback Sensing Technology (AFT), which electronically turns off the motor if rotation of bit is suddenly forced to stop, and Anti Vibration Technology (AVT) for reduced vibration. More than just a padded handle, AVT is an internal counterbalance that uses air pressure to move counterweight pistons in the