Not much to say on this, Denis Wick mutes seem to be the standard for British brass bands. The mute is well made and can be turned into a straight mute by slipping the cup of the horn. It works well and offers a pleasing sound to a muted Cornet.
I use this for my flugel mutes - though can only just squeeze the 3 mutes in here. Did a good job initially with 4-5 trumpet mutes - but have gone for the bigger trumpet mute bag. Squeezing 3 flugel mutes in here does make it a bit out of shape - but does the job.