IRWIN QUICK-GRIP One-Handed Mini Bar Clamp 4 Pack, (2) 6", (2) 12", 1964748
Unfortunately they’re out of stock, so shipping is estimated at 1-2 months, but this is the cheapest I’ve ever seen these and you can still place an order for when they get back in stock.
This is my first thread here, so my apologies if I missed anything.
https://www.amazon.com/gp/product/B00TKIUL84/