The TruTone is a Wales-based brand founded by Mark Adams, a woodworker and guitar builder also known for creating Jam Jar amplifiers. The company produces a single, focused product: a retrofit "second back" for acoustic guitars designed to increase resonance. The concept is rooted in a simple physics principle — a player's body mutes the vibration of a guitar's back panel, dampening its natural tone. The TruTone creates separation between the instrument and the player using a shaped wooden board mounted on three suction cups, allowing the guitar to resonate more freely.

The TruTone attaches non-destructively with no drilling or permanent modification required, and also serves to protect the guitar's finish from belt buckle wear. It is available in two tonewoods — ash and sapele — with custom left-handed versions offered by request. Adams developed the idea after watching a lecture on guitar physics and experimenting with how pushing the body of a guitar away from the player audibly changes its tone.