The impulse peak insertion loss (IPIL) is the standard measure of attenuation provided by hearing protection devices (HPDs) in response to an impulsive noise. This technical memorandum describes the IPIL testing conducted and the calculated mean IPIL values for the Honeywell Howard Leight(trademark) MAX(registered trademark) Small Earplug (Howard Leight(trademark) MAX(registered trademark) Small; Model: MAX-1S). Testing was done in accordance with the American National Standards Institute (ANSI) standard S12.42-2010. All samples were tested at the nominal levels of 160 and 170 decibel peak (dBP, re: 20 muPa). A total of five samples were fitted to an acoustic test fixture two times each for a total of 10 trials per test level. No samples were rejected. The mean and standard deviation (SD) IPIL values for each nominal level were 52.7 (2.0) dB at 160 dBP and 53.5 (1.4) dB at 170 dBP (see Table 1). The Howard Leight MAX Small (when properly fit and functional) will adequately protect (i.e., reduce exposure to less than 140 dBP) for impulses up to, but not including 180.0 dBP.