Bought these to finish the 3/8 inch rubber line. Straight back clamps are not suitable for this purpose (need round back clamps), pliers are cheaply made. The groove for the clamp is inaccurate, and therefore the clamp cannot be installed directly into the pliers, causing difficulties in use. The pliers are barely wide enough to hold the included 3/4" clamps, further complicating the "rectangle" problem. line: I made a poor choice and basically saved $15 on this purchase Trash thrown in. I hope others don't make the same mistake.