SUNLU Easy PA Nylon Filament - Warp-Free & Easy Printing with Nylon 6+66, Strong, Durable Engineering Filament on a PC Spool, 4kg in Total, 1kg per Spool, 4 Pack, 4000g, (4xBlack)

Well-known as much for their S1/S2 filament dryers as for the filament itself. The material catalog — PLA, PETG, ABS, TPU, silk — is broad and frequently discounted on Amazon. Solid all-around option.