Genuine Tone Ninja 19:1 Locking Tuners, 7 String 3x4 set, Black

They were dead easy to install into my Jackson JS22-7 Dinky. After a couple days of being installed, they hold tune very well with Trivium's signature Dunlop 7-string set of guitar strings! You can tell they're built with quality that is worth the money.

The best affordable locking tuners available. solid construction, reliable performance. Can be a bit stiff, but that’s easy to deal with and largely based on preference. The fact the 7th tuner accomodates larger gauges (up to a 0.85 iirc) is thr cherry on top.