Which LDFAS bands fit the Galaxy Watch (2018)?

Yes. LDFAS lists 1 compatible band for the Galaxy Watch (2018): LDFAS Galaxy Watch 7/6 Classic 鈦合金錶帶 – 彎扣 SSR.

What band size does the Galaxy Watch (2018) use?

The Galaxy Watch (2018) has a 42mm case. Compatible band width: Quick Release 20mm. First-gen small case

Yes — 1 LDFAS band are available for the Galaxy Watch (2018), each covered by a 2-year warranty.

Samsung42mmLug Quick Release 20mmSL20 Spring Pin 20mm

First-gen small case

Grade 1 Pure Titanium (99.5%+) — aerospace-grade, feather-light and skin-friendly.
Precision fit — engineered to the exact lug geometry of your watch.
2-year warranty on every LDFAS band.

Which LDFAS bands fit the Galaxy Watch (2018)?: Yes. LDFAS lists 1 compatible band for the Galaxy Watch (2018): LDFAS Galaxy Watch 7/6 Classic 鈦合金錶帶 – 彎扣 SSR.
What band size does the Galaxy Watch (2018) use?: The Galaxy Watch (2018) has a 42mm case. Compatible band width: Quick Release 20mm. First-gen small case
Are LDFAS bands compatible with the Galaxy Watch (2018)?: Yes — 1 LDFAS band are available for the Galaxy Watch (2018), each covered by a 2-year warranty.