I believe, these were used in both BUCKET seat and Bench Seat applications...They simply snap into the seat springs. Get in. Sit down. Turn ignition key on. BUZZER yelps to remind you "BUCKLE seat belts"!!! and in 72, some Buicks had the dash warning light that lit up as well, shown in last pix. I tested these contacts to ground and they operate as designed. We used to UNPLUG these silly annoying things... now they are cool to have in your factory original class. $15 each, shipped to any lower 48. Take all 3 or $35 shipped. Getin line here then PM me your intent. PayPal as Family & Friends or ZELLE. PenWheelz4@gmail.com Wheelz, Tampa Bay