The gutter connector is amazing. With its EPDM rubber (same type of rubber that seals cars or truck doors) it connects gutters together, and gutter with miters in a matter of seconds. Hang it from the back of the gutters, pull it towards you and fold the tab over the bead. Leave a small gap (1/8") between the gutters. Lock it into place by pushing up and securing the tab, you are done. Do not put any caulk, rivet or screws in this product. The gutter connector allows for expansion and contraction of the system. By the way did you know that steel moves half as much, and half as fast as aluminum, and with the EPDM rubber always staying flexible you will have zero leaks.