BLOCKALLS IFR View Limiting Device (Black) IFR View Limiting Device that simulates the true realism of IMC comfortably and accurately. Soft silicone nose piece, streamlined temple tips and light weight will make you forget youre wearing them. Streamlined ear pieces make sliding your Blockalls on and off while wearing your headset effortless. Designed with a soft opaque finish that blocks out distracting sunlight. Made in the USA of domestic and imported materials.