The Ventricle Razor is a use item introduced in the Afterbirth DLC. Its purpose is to create a portal on the ground with its first use. With its second use, that first portal is linked to the previous and acts as a transportation device within rooms. These portals last even if the item itself is traded and the effect persists even if you leave the room and come back later.
- While the razor itself may not hold much significance, the portals it creates do. Both are blue and yellow, reminiscent of Valve's popular 'Portal' series in which blue and yellow portals are fired at walls and floors to create a bridge.