Large on the left, Small on the right. Both sizes use a D60-3 or T12-3 squib to operate. The Large Glass Breaker or Popper is used for breaking tempered glass. The body of the breaker is turned from 7/8 inch (22,2mm) cold rolled steel bar stock and uses a small Hilti nail to notch and break tempered glass. A flat is milled on the side of the body for ease of mounting. On critical shots, such as a stunt person hurling themselves through a aheet of tempered glass, we always use two poppers.