The 40ft, 8 AWG, 3 conductor ETL listed cord has an industry standard NEMA 6-50 Plug and Receptacle, which are what you need for 40 amp circuits.
A heavy duty extension cord strong enough to use for welding and long enough to actually be useful.
The cord has heavy insulation to protect the wiring from chemicals and it is abrasion resistant, so when you drag it around the shop over concrete and through mystery puddles, you know you're still safe.
Allows you to move your welder around the shop and close to your welding work piece for added convenience.
Notes: Do not allow water or moisture to contact plug or receptacle when using cord.