This is an assortment of 7 automotive turn signal flashers that were made for the 50's to 80's automotive applications for cars and trucks. All 7 flashers are for 12 volt systems and will work with various brands of vehicles. These DOT-certified flashers have a durable construction and included are light duty for 2 bulb use and heavy duty units for multiple bulb systems. There are four different part numbers, with the blue flasher (P.N. LF224) an original equipment GM Part. These normally plug into the fuse block located under the dash. These flashers have old mechanical flashing technology and are not for use with new modern low current draw bulbs.