c. Retention Assembly (Figure 1-3). The yoke-style retention assembly minimizes forward rotation of the helmet and
reduces chinstrap stretch during use, thus providing a high level of protection. This assembly consists of V-shaped
straps (1) for vertical earcup adjustment, a rear hanger tab (2) for vertical adjustment of the nape area, an adjustable
chinstrap (3) with a double D-ring buckle, and adjustable rear nape strap (4) with a hook-and-pile closure for Individual
d. Earcup (Figure 1-3). The earcups protect hearing by reducing noise; they also flex to absorb lateral impact. The
earcups can be rotated within the retention assembly to optimize fit. Each earcup (6) features a cushioned earseal (9).
An earphone holder (8) and a filler pad (7) house the earphone inside the earcup. If further fitting is needed, spacer pads
(5) can be installed on the back of each earcup.
Figure 1-3. SPH-4B Retention and Earcup Assemblies