Ring spanners make contact with the full circumference of the fastener that they are turning, making them less likely to slip off than an open-ended spanner.
A ring spanner can come in two different profiles. A 12-point profile (bi-hex) or a 6-point profile (hex). Due to the profile of bi-hex ring spanners, they are able to lock onto fasteners in more confined spaces, because their 12-point profile gives the user more opportunity to encompass the fastener.
We sell a wide range of ring spanners, including double-ended ring spanners, slogging spanners, ratchet ring wrenches and offset ring wrenches as well as many other variants which you can find by using the filter on this page.