Joe Brown

Comparing a 3CU and a 4CU there is a reasonable difference in the width of the heads. The 3CU is narrower by one cam. This sounds pretty obvious, but sometimes it's not always the case. Other manufacturers will sometimes make a SLCD with 3 cams on it, but it will be only a small amount slimmer at the head. Fairly pointless really! Also DMM's 3CU has a slightly enlarged central cam. At the tip it is the regular width, but further up (where it's most likely to be placed against the rock) it's actually about 20% wider, which increases surface area, reduces pressure, and in doing so increases the chances of it holding in a fall, and reduces the chances of damaging the rock in the process.

One other slight advantage - 3CU devices are less prone to "walk" deeper into cracks than 4CU, as one side of the device just rotates against the rock.

These are a very nice addition to an existing rack of camming devices.  Maybe not as first buy, as the narrowness of the head does reduce the stability a little. However, they will certainly be one of those items which you're glad you had it when you needed it!

Available in size 0 - 1.75

Also available individually   (see separate listing)