ADJUSTABLE SIZE - Fit boards with a thickness of 3/16" - 3/4" for 90 degree corner and T-joints, also apply to assembly two board with different thickness SMOOTH STRONG SPRING - High spring tension to keep boards in place when screwing or gluing them together SINGLE HANDED OPERATION - It allows you to open this clamp with one hand,and hold workpieces together with the other HIGH EFFICIENCY- The advantage of having 4 pack angle clips is that you can square and set entire side of wood box in one GREAT SET for ARTS and CRAFTS - Perfect for small wood working project, to build wooden boxes, picture frames, birdhouse,mailbox, dresser drawers assembly