ProtoArc Wireless Trackball Mouse, EM01 NL Ergonomic Bluetooth Rollerball Thumb Rechargeable Computer Laptop Mouse, Adjustable…

Across the reviewers we read, the ProtoArc EM01 NL has built an unusually devoted following for an affordable thumb trackball. r/Trackballs posters repeatedly single out its 34mm ball and bearings: one wrote it "rivals the Ergo and the MTO" for feel, another found it "super smooth" and a third called it "much more pleasant to use because of the superior ball/bearings, the grippier bottom, and the more comfortable shape." custompc.com adds that it is "comfortable, has plenty of buttons and the ball itself tracks accurately and smoothly." Its 4.3-star Amazon average across 3,301 reviews reflects that broad approval.

Reviewers frame it explicitly as a value alternative to the Logitech MX Ergo, with multiple YouTube reviews billing it an "MX Ergo slayer" and a flatter design that suits people who like to rest their hand on the trackball. The caveats are the usual thumb-trackball ones plus a profile that won't fit everyone: the flatter shape is praised by medium-to-large-handed users but may feel less sculpted to others, and "thumb dexterity notwithstanding" there's the standard adjustment period. Because the supporting evidence is overwhelmingly community and unknown-tier rather than independent lab testing, the consensus is enthusiastic but not independently verified.