Ring ratchet spanners, also known as combination ratchet spanners, are versatile hand tools used for tightening or loosening fasteners, such as nuts and bolts. They are designed to provide both a box-end wrench and a ratcheting mechanism in a single tool.

The spanner features a ring-shaped or open-end wrench on one side and a ratchet mechanism on the other side. The ring end has a closed loop with a specific size and shape to fit the corresponding fastener. It usually has a 12-point or 6-point configuration to provide a secure grip on the fastener without slipping.

The ratchet mechanism is located at the other end and allows for convenient one-way motion. It enables the user to turn the fastener without having to lift the spanner off the nut or bolt. The ratchet mechanism typically has a switch or lever that allows you to change the direction of rotation, making it useful for both tightening and loosening.

The advantage of using ring ratchet spanners is that they eliminate the need to remove and reposition the spanner for each turn. This makes them particularly useful in tight spaces where a full swing of the spanner is not possible. The ratcheting action enables faster and more efficient work compared to traditional open-end or box-end wrenches.

Ring ratchet spanners come in various sizes to accommodate different fastener dimensions, and they are commonly available in metric or imperial measurements. They are widely used in automotive repair, mechanical engineering, plumbing, and various other applications where fasteners need to be tightened or loosened.