Description Lancer Tactical 8-Hole Flat Aluminum Piston Head w/Bearings - Blue (CA-540) Features: Ported piston head face Durable full metal ball bearings and washers at the rear of the piston head 8 Ported piston head vents for maximum compression Durable and lightweight construction 2 Thick piston head O-Rings Color: BLUE Construction: Aluminum Alloy Weight: 11.2 g