Abstract: An anti-polish ring for an internal combustion engine is provided. The anti-polish ring includes an axially extending ring portion that is configured to scrape a top portion of a piston in a cylinder liner. The anti-polish ring is configured to accommodate passage of an intake or exhaust valve thereby. The anti-polish ring may include an alignment feature so that the anti-polish ring is inserted in a predetermined orientation in the cylinder. The anti-polish ring may include a heat shield and/or a seating member.

Abstract: A protective communications helmet combining aural, visual, flying object d bump guard protective features with electronic communications including a multiple section shell comprised of a central shell to which lateral electronics compartments are removably attached. The central shell and lateral electronics compartments are of generally planar design for facilitating packaging density and thereby enabling an extremely low center of gravity, reduced moments of inertia, and lower packaging weight. The helmet further includes a suspension system having adjustably secured attenuating, fitting cushions disposed on the inner surface of the central shell and positioned to avoid the Sagittal suture. A nape pad is adjustably secured to the rear portions of the lateral electronics compartment. The helmet is equipped with an externally adjustable universal sizing headband. Mounted on the headband are adjustably fitted side pads and a rear head pad.