Vencetmat 4mm & 5mm Truss Rod Wrench, Allen Wrench Tool Ball End for Martin Acoustic Guitar Truss Rod Adjustment And Deep or Narrow Truss Adjustment.

For martin or other guitar which couldn't reach it with a regular hex wrench truss rod adjustment., Two way L-shape truss rod adjustment tool., Made of carbon steel, durable and highly wear-resistant., Set for most kinds of acoustic guitar, electric guitar and bass., For locking hexagonal screws on the bridge, adjusting the guitar neck.