Hallco Mag beads Magnesium oxide C. P. Hall Acid Absorber / Acceptor Chloroprene Rubber (CR) ADHESIVE HALLCO MAG BEADS is a combination of a lower activity magnesium oxide and a process oil, resulting in a highly dispersible, free-flowing additive well suited for non- critical, polychloroprene-based elastomers and adhesives Highly dispersible, free-flowing acid absorber. Combination of a lower activity magnesium oxide and a process oil. Used in polychloroprene-based adhesives.