The CG Regulator has an overflow level indicator to allow visual gas level monitoring and convenient leak testing. The added safety feature EFV (Excess Flow Valve) comes as standard. EFV is an automatic hose safety feature that automatically cuts off 90% of gas flow if the hose is compromised. Features and Benefits Suitable for 901/904/907 Refillable Cylinders 28mbar CG Regulator With Quick Release Fitting Overflow Level Indicator EFV Excess Flow Valve Safety Feature 85cm Crimped Hose Additional Safety Features As Standard Specifications Dimensions: H:33.0 x W:24.0 x D:7.0 cm Guarantee:1 Year Model Number: 8515-FL-QR