Greenhouses Polycarbonate Greenhouse Panels Connectors - 0.15" Thick, Fits 4mm Twin-Wall Polycarbonate Panels, Join 2 Pieces of Panels Together, 4-Foot Length, 10 Pieces (H Connectors 4mm-4ft)

These are perfect for the polycarbonate greenhouse panels that we purchased. I will be reviewing those later, if you want to go to that review to see which one's worked with these. I was a little concerned because the descriptions are hard to understand to know which ones will work. The ones that were linked to our polycarbonate panels we're not going to even ship until june, and we couldn't wait that long. So I took a gamble on these. And I'm glad I did. There are perfect our greenhouse roof is gorgeous. Everything's fit together perfectly. We did not have to cut any of these so I can't tell you how easy they are to cut. But functionally they are fantastic. They are great value for what you're getting. They seem nice and durable so far. I'm hoping they'll stand the test of time, but only time will tell that.One tip. If you're having issues getting them to slide onto your polycarbonate panels, dawn dish soap is your best friend. Just put a tiny bit on the edges of the polycarbonate panel and it'll slide right in.

Decent quality hard to seal panels together

These H channel connectors fit nice and tight over the panels I have. Standard thickness and sturdiness for this type of material. Will hold but won't take any abuse.

These did not work at all! Don't waste your money. No flexibility and too tight to go onto panels. Awful quality!

As an avid gardener, I'm glad to have these connectors and have at least a couple of uses for them in mind, including building small portable "greenhouse" covers for certain cold hardy plants that can grow well into the winter like kale, spinach, etc.. Also, I'll be assembling a large greenhouse this fall and it will be nice to know that I have backup connectors in case I break one or two that came with the greenhouse. I always like having that kind of insurance.

Totally useless. These do NOT seal anything! Just finished my install. A week of work and money wasted! One quarter inch rain, and every channel of every polycarbite panel has water in them. Have to disassemble everything, let the panels dry out and simply seal and attach everything with silicone. Should have done it that way the first time.