Like many artists, I find inspiration in the late hours of the day and evening, much to the chagrin of my wife and neighbors. Prior to the Artino PM-02, we cello players had only two options for quiet mutes - all rubber or all metal. Who would have surmised that combining the two would be the best of both worlds.
All metal (hotel mutes) are most effective but a hazard if you drop it on your cello! You also risk damaging the wood of your bridge from repeated use. All rubber are safe to use but not as quiet. The Artino PM-02 is has a metal core and silicon(?) coating, which is as like using a metal hotel mute with less risk of damage.
NOTE: works better with French bridge. Though mine is Belgian, it functions good, hence the 4 stars.