I use it with my MixPre 3 in different variations of powering. Although the MixPre 3 kind of hangs inside if using the power bank, with the Li-ion batteries mount (with 2 pretty large batteries from both sides) it fits good in and works pretty well. Managed to fit also a Raspberry Pi with another powerbank, so that I have an independent system for sound processing. However, I took away one star, because with long time walking and carrying it around (with large powerbank or 2 batteries) the shoulder gets tired pretty soon, so I had to buy an extra softening silicon pad. (that's why one star less for the comfort). Also to mention, the plastic connection between the zippers could be stronger, mine broke unfortunately very fast. To sum up, very happy with my choice.