Ladder Press

Ladder Press (ラダープレス) is a spiked hand-like press that goes up and down in a ladder opened, and closes in the borders of the ladder. It is used to patrol ladders and prevent invaders. They can't be destroyed and do not freeze with Flash Stopper and Spark Shock. They appear in the first and second stages of Dr. Cossack's citadel in Mega Man 4 and Snake Man's stage in Mega Man III.

Mega Man Network Transmission
Ladder Press appears as a virus in the Outer Net, near the Legendary WWW Area entrance. Unlike the originals in the Mega Man series, these can be destroyed.