The mat you actually take out.
Most training mats sit in a corner because they're either too thin to protect you or too bulky to move. This one folds flat, stores against a wall, and is on the floor in under ten seconds.
Non-slip surface. Adequate thickness for floor work, stretching, yoga, and bodyweight training. Closed-cell foam doesn't absorb sweat.
The best training tool is the one you use consistently. This mat removes the friction.