This is a set of the most popular Camp Tri Cam sizes (0.5, 1, 1.5, 2). These are also anodized and on dyneema tape, rather than the standard nylon. Camp tri climbing cams are versatile, lightweight and compact, working well where other nuts and cams are almost impossible to place, such as narrow pockets and peg scars. This is due to the fact that they operate using a single camming unit, allowing them to be placed in very narrow positions where spring-loaded camming devices (Friend's Camalot's etc.) will not fit. All the smaller sizes are particularly good in this sort of scenario, with sizes 2 and 2.5 being the right size for many quarry shot-holes.
In their simplest mode Tri Cams can be placed like a standard chock/nut. However, to take advantage of a Tri Cams full potential in cracks, scars and solution pockets, position the attached sling down between the camming rails, insert into the rock and then give the sling a good yank to "set" the unit. To add security to the placement you can locate the point of the unit in a small depression or place in opposition with another nut.
One of my favourite bits of gear, these will place where nothing else will. You can use em as a passive nut placement or utilise there excellent camming ability. The pink one is one is my personal favourite.