In this picture there are three types of line adjustment and leak path insulators. The top one is made by Fleron Radio and is called a Aerial Spring. Designed to take the slack out of the aerial line and keep it taught and not sag. Wish I had the whole kit for these but the two small insulators are part of a Twin Leak aerial break. Made by the Twinanteleak Aerial Insulator Mfg. Co. Plainville, CT.,There were usually two U shaped brackets with insulators on them in the kit. Last is a Birnbach Radio Antenna Adjuster. Does the same thing as Flerons spring but a different design and name.