Linear Hack Press.

Straight path. The rest is decided with the feet.

The sled runs in a straight line, and that is the whole difference: the load comes from the same direction from the first rep to the last, so neither knee nor hip is forced off course towards the end of the set the way a free squat tends to when you get tired. Where you place your feet decides what burns, a high foot position moves the work towards the glutes and hamstrings, low towards the quads, and you can switch between sets without adjusting anything. The frame weighs 190 kg, is only 1160 mm high and takes 1650 × 1050 mm of floor. Move the feet, change the exercise.