Water and pressure tight cable gland and you can use these cable glands for E/O cord , it has a rubber tube to prevent the cable from breaking.

Cable gland provides the transfer between light cord and canister.
By incorporating the strain relief into the sealing gland, reduce the damage of the light cord.
This is suitable for Standard or E/O cords used on Halcyon dive lights like Flare, Focus, Explorer and Eos. It can be use for other diving torches.
The strain relief can improve cord life and keep lights use longer between services
Replacement Sealing Gland for Dive Torches
M16X1.5 thread
Cable Connector Gland and Strain Relief