These were a very popular mouthpiece made by CE Winds. They came in many forms, Jumbo Blue, Hard Rubber, Brassite, Alumilite, & Cooperite. Modeled after the Vandoren Jumbo Java that was made famous by Warren Hill. This one available is brand new B Stock (cosmetic blemishes) and is Alumalite. Which is a super lite metallic resin hybrid piece.
There are many videos on YouTube of players using these. The item "CE Winds Mainstream Jumbo Java A45 Alto Saxophone Mouthpiece" is in sale since Monday, November 16, 2020.
This item is in the category "Musical Instruments & Gear\Wind & Woodwind\Parts & Accessories\Mouthpieces". The seller is "wwwsaxmallcom" and is located in Jacksonville, Florida. This item can be shipped worldwide.