104PCS 4 6 8 12 16 20 mm 4:1 Heat Shrink Tubing Double-Wall Adhesive Lined Wrap Tube Assortment Kit Black

Been a fan of 3 to 1 shrink for a while. Wanted to try 4 to 1 in a few applications where 2 layers of 3 to 1 were needed. This stuff did it in one layer.

I tried to fix this cable with a different heat shrink tubing. That tubing had a shrink ratio of 2:1. If you use a diameter large enough to fit over the thunderbolt connector, the 2:1 shrink would not shrink tight around the cable. This tubing is a 4:1 shrink ratio and it worked perfectly. It also has some glue inside the tubing which will glue the shrunk tubing around the cable. Not sure I need that and would make it difficult to remove if I had to, but now that it is on, the glue really makes it a solid fix. I also used Bondic inside the tubing to seal the split cable insulation. Recommended for any application like a cable with a connector that you need to pass over.

I used the 8mm tubing on my macbok pro mid 2012 charging cabel, which had the rubber exterior starting to peel off at one point near the adapter at the computer end. Slid it over the adapter to rest on the failing cable section, and shrunk it down. Now a repaired and stronger cable, and looks clean. I specifically got this for 4:1 ratio, so that the 8mm would shrink down to the 3mm cord. PERFECT.

I was really excited to purchase these, and start putting them on ALL of the dozens and dozens of charging cables, cords, etc. They are thick and heavy duty, but are able to stretch some in order to fit it over the end a given cable (example, the lightning cords for Apple and the USB-C cords that seem to be getting more popular). However, my only gripe (and I'm really not sure if this is the manufacturer's "fault"), but it was kind of annoying that every size was either too small or too big. The sizes that had the most pieces were definitely too small, and I literally spent hours trying to stretch/push/pull/wiggle them on to the lightning cords. I was successful 2 out of 5 times before I gave up (2 tore before I was able to get them completely over the head/end of the cable, and 1 I just finally gave up on because there was no way it was going to work); I wound up using a larger size (I think 8mm?), which of course, was the size that had the least amount of pieces. I was worried that the larger size would not shrink enough, but it seems to have worked; not the nicest, cleanest, neatest looking, but it worked). The "glue" on the inside (I guess the part that makes it waterproof) tended to leak out the ends and make a little gooey mess on each end, but nothing major or disasterous. The 2 smaller sizes I was successful in stretching (6mm I think?), took forever to get over the ends, but once I was successful and applied heat, they made a great seal, no mess, and looked picture perfect; however, I just couldn't do it anymore, my fingers were sore and raw, and I couldn't even close my hand when I finally gave up. The 8mm size went right on, zero resistence, but once they were shrunk they tended to leak the glue and goop up on each end, and I'm not positive that they shrunk down nice and tight like the 6mm. Once cooled/dry, they did not move at all, so they seem to have worked. Bottom line, they do the job well, and they have saved many, many cords from early fraying/breakage (my kids used to go through charging cables every couple of months, no matter how gentle they swear they are with the cords, but they have not broken or frayed any cord since I reinforced them with this heat shrink tubing. I would buy again, but would hope to see that they have a different size; either way though, I would still definitely buy again if/when I need more.

4-1 shrinkage seems to be accurate, and the adhesive seals and waterproofs effectively. When cooled any excess adhesive squeeze out is hard and clear, not sticky.

Definitely shrinks a lot compared to others out there. Nice and thick and the glue is strong.

I needed some super-shrinking tubing to use when I couldn't cut a connection off and this did the trick. WARNING, it super-shrinks both in diameter AND length compared to normal shrink tubing. Adhesive is a bit messy, but cleans up easy enough.

The tubing is fine and does what it's supposed to do. But I don't think it's 4:1 like advertised. More like 3:1. The plastic case is really thin and was broken when it arrived. This item is not eligible for return. Hopefully I can get amazon to give me a refund just for that.