The Bessey WS angle clamps differ quite a bit from your standard corner clamps. They’re designed to hold, fix, and align material at a 90° angle, and they adjust to variations in wood thickness. They also feature a slot in the clamp, so you can drive fasteners in the joint while the glue’s drying, without the entire piece shifting.
They look pretty handy for furniture assembly and framing, plus they’re pretty small so you can throw them in a drawer or toolbox when they aren’t needed. We can definitely see ourselves taking advantage of the added slot in the clamp. If you think you need these, you might have to hurry, though — we’ve heard a rumor that Bessey’s going to discontinue them soon.