The clearly secure 3 in. thick series glass block hopper-style vent is designed to work with 3 in. thick glass block. This nominally sized 16 in. x 8 in. vent is used in place of two 8 in. x 8 in. x 3 in. glass blocks when assembling a glass block window using individual blocks. The convenient size allows access to fresh air without compromising security. It may be used with either the mortar or silicone method of glass block assembly. Existing glass block windows can be modified to add a fresh air option. The included screen is mounted on a removable frame making screen replacement easy.