VEVOR E Track Tie Down Rail Kit, 5' Steel Rails, 4 Pack, Secure Cargo & Heavy Loads Up to 2000 lbs, Heavy Duty Etrack Rails with Screws for Garages, Vans, Trailers, Motorcycle Tie Downs, ATV Mountings

It is M6.

No,you can't buy just two 5' e-track [black].This product is sold as a complete set.

The product description states that this is suitable for trailers, pickups, trucks, vans, etc. and adapts to any environment. However, customers report issues with the product and customer service.

Yes, the product description states that it can be mounted on trailer floors. The E-track rail kit supports multi-scenario use, including wall mounting, floor mounting, and bolt fixation, and is suitable for trailers, pickups, trucks, vans, and other environments.

The product description states it is crafted from industrial-grade solid steel with a fine powder coating that promises a long service life without rusting or corroding, even in harsh environments.