The BD Stoppers have a very similar side profile to DMM's Wallnuts but are almost square on the front, making them ideal for cracks with very little taper. While you obviously would have trouble climbing with one of every nut on the market strapped to your harness, it is definitely worth having a selection across the board and these have the added bonus of being cheaper than most of their competitiors.

Size one only has a 2kN strength rating and BD say use for direct aid only.
Weight: 7g
Red