Allen Company ULTRX Bionic E-Muff, Electronic Earmuff, NRR 22dB, Rubberized Protective Coating, Midnight Gray 4108 Allen's comprehensive lineup of hearing and eye protection under the ULTRX brand. From foam ear plugs to electronic eBuds, the ULTRX lineup is a complete solution for hearing protection focusing on the broader needs of hearing protection. From vibrant color pallets to high performing electronics, the Allen ULTRX brand covers all possible formats, functions and sizes.