HEMPER Matrix Stack BongDescription The HEMPER Matrix stack bong features a super smooth Matrix percolator, as well as an ice pinch for an even smoother pull if you've got ice on hand! Matrix percs have a unique function in that the push air in almost every direction except for up and into your mouth! Combined with this bottle styled chamber, all water is deflected back down into the bottom, to filter once again in perfect sequence. This is a clean piece with functional