The Lezyne Twin Speed Drive CO2 is a CNC machined aluminum dispenser with brass internals. Slip-On Valve Operation allows for quick inflation. Twin Slip-Fit head presses onto Presta and Schrader valves. Two piece head allows for easy O-ring replacement. Neoprene sleeve insulates hand from cold during discharge. Compatible with threaded CO2 cartridges, comes with one 25g cartridge. Features Aluminum Construction – A lightweight and durable construction used throughout our line to create elegant and functional products. CNC Machined – CNC machined aluminum parts for precise and durable construction. Thread Valve Operation – Simple twist on/off operation efficiently punctures the cartridge and regulates CO2 release. Compatible with all threaded CO2 cartridges. Slip Fit – Presta only, slip fit design presses onto valve for instant engagement.