Q7946A Revision 0 EN352-9

2. PAGE 2 OF 2 T able 2. Mean in ear noise levels using p50_f dB FS p50_f dB FS Mean (dBA) SD √Sum of squares Mean + √SS (dBA) - 35 66.8 0.3 3.0 69.8 - 30 66.8 0.3 3.0 69.8 - 25 68.5 0.3 3.0 71.5 - 20 68.9 0.2 3.0 71.9 - 15 69.3 0.2 3.0 72.3 - 10 69.6 0.2 3.0 72.6 Michael & Associates is accredited by the National Institute of Standards and Technology (NIST) National Laboratory Accreditation Program (NVLAP) for tests performed according to ANSI S3.19 - 1974, ANSI S12.6 - 2016, AS/NZ S1270:2002 and EN352 parts 1 - 10. These accreditation criteria encompass the requirements of international standard ISO 17025. This report may only be reproduced or transmitted electronically in its entirety. This report shall not be used to claim product approval, certifica tion or endorsement by NIST, NVLAP or by any agency of the U.S. Government. All measurement equipment are calibrated with instrumentation traceable to the NIST. Accreditation documentation can be viewed at www.michaelassociates.com/data/documents/NVLAP - 2023.pdf . Kevin Michael, Ph.D. President R² = 0.9022 50 55 60 65 70 75 80 85 -40 -35 -30 -25 -20 -15 -10 -5 0 dBA p50_f ( dB FS) Bluetooth transmission linearity check and visual reference to 82 dBA threshold limit Mean + √SS (dBA) Exposure Threshold

1. PAGE 1 OF 2 Test Report ID: Q 7 946 A Revision 0 Opsmen Tech Co., Ltd. Room 601, Building A, No.94 Liwan Road, Liwan District, Guangzhou, China Date of report: 1/ 3 1 /2 3 Date of sample receipt: 1 1 / 22 /22 Dates of testing: 1/ 30 /2 3 Technician: Sandar Bregg Table 1. Test Result Standard Maximum Output & usage time EN352 - 9 :2020 The maximum output level of 7 2 .6 dBA was less than 82 dBA , the usage time is >8 hours Acoustic testing was performed on M20/ M20T electronic earplugs according to EN352 - 9 :2020 for Bluetooth transmission ( Test ID Q7 946 A ). For the EN352 - 9 :2020 testing, a G.R.A.S. 45CB fixture was tested on each of the four samples twice for a total of eight measurements or 16 ears. The mean, standard deviation, and square root of the standard deviation’s sum of squares at each of the noise levels were calculated and presented in Table 1. Individual data is presented in the appendix. Noise levels tested ranged between - 35 dB FS to - 10 d B FS in 5 dB increments. For all tests, t he test signal was a simulated female speech according to ITU - T P50_F:1999 and volume controls were set to maximum . The maximum output level of 7 2 .6 dBA did not exceed the 82 dBA threshold limit and passed this test. 2766 W. College Ave Suite 1 State Colleg e, PA 16801 814 - 234 - 7042 phone 814 - 235 - 1381 fax Email: Kevin@michaelassociates.com URL: www.michaelassociates.com Figure 1 . M20/ M20T electronic earplugs

3. PAGE A - 1 Table 3 . Individual in ear noise levels in 5 dB increments using p50_f dB FS Device / Trial Side of head p50_f (dB FS) - 35 - 30 - 25 - 20 - 15 - 10 DFE Correct individual in ear noise levels (dBA) 1/A Left 66.8 66.8 68.6 68.9 69.1 69.4 Right 66.7 66.7 68.5 68.7 68.9 69.3 1/B Left 66.9 66.8 68.6 68.7 69.2 69.6 Right 67.0 66.9 68.7 68.9 69.4 69.8 2/A Left 66.7 66.6 68.2 68.5 69.1 69.2 Right 67.3 67.2 68.8 69.1 69.6 69.8 2/B Left 66.8 67.0 68.5 69.1 69.4 69.5 Right 66.8 67.0 68.4 69.1 69.5 69.6 3/A Left 66.9 67.0 68.7 69.0 69.4 69.5 Right 67.0 67.1 68.8 69.1 69.5 69.6 3/B Left 66.9 66.8 68.5 69.3 69.6 69.9 Right 66.4 66.3 68.1 68.9 69.3 69.6 4/A Left 66.5 66.5 68.2 68.9 69.2 69.5 Right 66.6 66.6 68.3 69.0 69.3 69.6 4/B Left 67.0 67.2 69.0 69.2 69.7 70.1 Right 66.3 66.6 68.3 68.6 69.2 69.6