G-Lab (Guitar Laboratory) is a Polish manufacturer of guitar effects and switching systems based in Warsaw. The company is best known for its Guitar System Controllers — programmable switchers like the GSC-3, GSC-4, and GSC-5 that combine effects-loop routing, amp channel switching, and MIDI control in a single floor unit aimed at professional touring rigs.

Alongside its controller line, G-Lab builds a catalog of hand-assembled effects pedals including the Wowee Wah (WW-1) and its bass and MIDI-controllable variants, the Dual Reverb DR-3, Quiver Reverb QR-1, Spectral Verb SV-1, Smooth Delay SD-1, Clutter Chorus CC-1, Chaos Drive CD-1, Uproar Fuzz UF-1, and Adrenaline Booster AB-1. The brand also produces the LMS-1 Line MIDI Switcher and MGC-6 MIDI foot controller, rounding out a product line oriented around integration and signal routing.

G-Lab's circuits emphasize a true-passive signal path with electro-mechanical relay bypass, a design choice that has earned the brand a niche reputation among guitarists building complex switched pedalboards and stage rigs that need MIDI-recallable presets without tone loading.

G Lab has 5 products cataloged on Equipboard, including Multi Effects Pedals, Delay Effects Pedals, and Switch Effects Pedals. Their gear is featured by 7 artists, with the strongest followings in Rock, Metal, and Blues. Notable users include Mark Tremonti, Michael Hoggard, and Yusuke (Lynch).