Small diameter bendable conduit?

Came across this today in a basement, likely done by the homeowner. Very small diameter conduit which is flexible almost like copper tubing. There are four 14AWG conductors in here! Has anyone ever seen this before? It’s a first for me. Any input appreciated…

Do not know where it comes from and clamps do not appear to be conduit clamps but those intended for romex. I believe you have an improper use of materials. and likely no permit or inspection.

Looks to me like alu-sheath cable had a very short manufacturing life span I think it was about 1960 + we used it . 2 & 3 wire #14/12 the casing was the ground .

https://www.nachi.org/forum/f79/type-electrical-wire-108154/

Looks like it might be smooth sheath MC cable which is still recognized by the NEC. Admittedly I’ve never seen it.