Rather than teeth, these wrenches use a series of rollers to engage the ratchet, enabling work in the tightest of spaces. Also known as silent ratchets, they don't make the traditional click sound when turned. To reverse the ratchet, remove the square drive and insert it on the opposite side of the wrench head. The square drive is held in place with a retaining ring and requires pliers for removal. The smaller the turn required to ratchet, the less clearance you need to engage the ratchet.