V.one Heavy Duty Tie Down Straps with Cam Buckle 2 PK -772 Lbs Load Cap Nylon Quick Release Lashing Straps for Cargo Tie Down, Car Roof Rack, Luggage Kayak Carrier, Moving Canoe and Hammock

These are NOT "Heavy Duty". The buckles are lightly built. More light weight than all other such buckles I have seen. "Heavy Duty" would mean at least as strong as the typical buckle and really something stronger. I didn't test it, but I would not put 772 lbs on these straps.

I use these to tie down kayaks.

Generic construction for a good price.

works good - just what we needed to secure our kayaks to the vehicle

Just what I needed