I bought that fluo tape for several purpose:
1) Clear labelling on my instrument cases (I wrote on it with a permanent marker and it's brilliant)
2) Wrapped my cables' plugs, so I'm the "green guy". This way I can see if the cable is mine, if I forgot something on stage and people now it's not theirs.
3) When you have several pedals at your foot, you use different inputs for different cables, etc: the labelling makes everything so much easier when you have a very limited time on stage to put your gear. You know where to plug, no bad surprise.
Also, I'm a gaffer tape user since several years (for music and photo) and I love that this tape is a canvas-gaffer-type tape. It's very strong, hold in time, glow when light is low. It's the best for me!
