Each order of Heatshrink comes with 1½” (39mm)-long pieces of heatshrink, which are long enough to neatly cover any of the connectors we offer.
This heatshrink has a 3:1 shrink ratio.
Which size do I need?
It will depend on your use case, but we use the 3/8" size for pretty much everything. You may want to use the 1/4" size for TRRS connectors if your cable has double-sleeving. The smaller diameter will allow it to fit better underneath the TRRS connector barrel. You can also use the 1/2" size to fit over USB Type-A connector shells if you prefer not to have to stretch the 3/8" size.
Tip: On Type-A connectors, you will likely have to stretch the 3/8" heatshrink out a little bit to make it fit over the shell. We use a needlenose pliers :)