Upon impact, Nosler's exclusive E2 Cavity [Energy Expansion Cavity] allows for immediate and uniform expansion, yet retains 95% weight for improved penetration. The E2 Cavity provides amazing stopping power and peerless penetration over a broad spectrum of impact velocities, rivaling even the highest quality lead-core bullets. Signature OD green polymer tip - Nosler's advanced polymer tip initiates expansion while delivering unsurpassed penetration and weight retention ECR - the expansion control ring insures controlled expansion at a wide range of velocities and conditions, making the E-Tip very versatile E2 cavity - the exclusive energy expansion cavity provides a dual-expansion chamber for amazing stopping power and uniform expansion with 95%+ weight retention for superior penetration Solid copper alloy construction - Nosler's 1-piece design meets all "lead-free" hunting regulations Boat tail design - boat tail configuration combines with the streamlined polymer tip for extreme long-range performance and for easier loading