TTB-6, Barrel Lock Plunger Key The TTB-6 Barrel Lock Plunger Key is compatible with several types of Highfield and Innertite barrel locks with inside diameters ranging from 0.176” to 0.196”. Compatible with Channell Highfiled and InnerTite CATV barrel locks. The barrel lock plunger key is compatible with several types of Highfield and Innertite barrel locks with inside diameters ranging from .176" to .196". Works on Channell LK03029817, Highfield 93180775-S. This key may also fit other locks used in the electric, gas and water utilities. Know your lock size before purchasing.Item Type: Barrel Lock Plunger KeyManufacturer Part Number: TTB-6The key is made of high carbon alloy steel, designed for heavy duty use and engineered for superior tamper resistance. Smooth plunger and heavy duty spring for strength and durability, and serialized for added security. Works on Channell LK03029817, Highfield 93180775-S.Inside diameters ranging from .176" to .196"