Mono M80 Dual Electric Bass Guitar Gig BagA second bass is a must have on stage or in the studio. But in transit, carrying two bass guitars has always been a necessary evil. Mono set out to design an elegant solution to this problem. Mono's driving criteria was to offer each guitar the same protection as their single M80 hybrid case. After a year of prototyping, the Z form design was perfected (patents pending). The end result is an incredibly light weight, extremely rugged double hybrid