Check the listing for details. 6PK Construction Concrete Forms Wood Fences Walls Posts Frames Aligning Tool Set. Condition: New. Listed at 9.99 USD. Pack of 6 Aline-Sets are small, flat pieces of polycarbonate resin that replace the 2x blocks that most framers nail in the corners of a stud wall to secure their stringlines for wall straightening. The setup can be used with three of the plastic blocks: one on each end of a wall and a third (or a tape measure) to gauge the straightness of the wall along the length of the string. Each piece—which has notches that can hold the string at four different measurement positions—is secured with one or two nails and is easy to remove with the claw of a hammer after use.Aline-Sets won’t bog down your tool belt and are easier to use and more accurate than old-fashioned 2x blocks. They’re great for any straightening or aligning process that involves stretching a string, from deck posts to foundation forms.