The Sphincter offers limited protection in marginal situations such as iced-up cracks and some thin ice situations where conventional screws or hooks are useless. However, where they really shine is in seams and direct aid situations.

The definition of "thin ice" depends upon whether you are climbing the ice or using ice for protection. For example, ice two inches thick does not require any different climbing technique than ice twenty inches thick. If you are not running the risk of blasting your tool through the ice and hitting rock it is not "thin ice" for climbing and requires no special tool placement technique.

However, ice two inches thick is clearly "thin ice" from the point of view of protection. Tied-off screws do not offer much protection in such situations. Neither do conventional hooks. It may be reasonable to climb ice that is too thin to protect, and rock pro may not be an option. In these situations, a special tool is needed.

The best ice placement for Sphincters is in a vacated tool placement. Slip a Sphincter into the hole made by your tool. Tap it in gently until its stem is against the ice and clip in.

Do not expect a Sphincter to hold a hard fall when placed in ice. Always try to have some good pro as back-up below. If you have a lot of rope out, the Sphincter could conceivably hold a very short fall, or help as a back-up of other pro. If you have only a few feet of rope out, don't expect it to hold much at all.

So often in difficult situations, you can place pro above your head and get limited protection for a move. The Sphincter falls into the category of limited protection in thin ice. Think of it as having the fall-holding capacity of a tiny micro nut/RP.

Sphincters work well in vertical cracks or iced-up cracks, aside chock stones, or in frozen moss or mud. Serious climbers are discovering that an excellent application for the Sphincter is for direct-aid on rock! The versatility offered by the Sphincter makes it particularly useful for mixed climbs that may require unconventional rock and ice pro.

Above all, climbers must understand that the reliability of the Sphincter depends upon its user being skilled at dealing with the conditions in which it will be used. It is not foolproof. It is limited protection and is difficult to place well in ice. However, in extreme situations on ice and as a direct-aid device, it is often the best thing you can get in - sometimes the only thing.