The mandola is to the mandolin what the viola is to the violin, a slightly larger instrument tuned a fifth lower. In practice this means the double courses are tuned C-G-D-A instead of G-D-A-E. Interestingly enough, it has been part of the Collings lineup for about as long as their mandolins. This archived Mandolin FAQ webpage (2016) lists serial numbers for both mandolins and mandolas, interspersed and not separated by model, confirming a similar approach taken by the manufacturer as for their ukuleles. However, the mandola only comes in the traditional A-style, though still in 2 distinct styles. The MT2 Mandola is the most luxurious, i.e. with ivoroid binding for the back of the body, ivoroid bound fingerboard, Flourish headstock inlay, and gloss nitrocellulose lacquer finish. An MT Mandola lacks the aforementioned adornments and has a satin nitrocellulose lacquer finish. What they share is a tortoise bound Adirondack spruce top, f-holes, tone bars bracing, adjustable ebony bridge, Collings original tailpiece, Eastern flamed maple back, sides, and neck, the latter having a rounded-V profile, ebony fingerboard with 7”-15” compound radius, Mother-of-Pearl (MOP) dot position markers, 15⁄16” bone nut, and “Haircut” headstock with ebony veneer, MOP logo, and Gotoh tuning machines with either ebony or ivoroid buttons. The Mandola comes in a deluxe TKL OHSC. As of 2025, MT(2) Mandolas are still in regular production. More info on the MT Mandola can be found here:

https://www.collingsguitars.com/mandolins/mt-mandola/.