I started off with 10lbs and did some back exercises like dips and situps and just went a bit of time with it. then moved up to 20 and did some stretches like yoga.
but just keeping it on during the day if you can does a lot too. just dont go overboard with it.
I got mine at Dick's Sporting Goods. It says "Fitness Gear". It's not that different from this one on Amazon.
Looks good but wow $205. I am eyeing this one for $40 https://www.amazon.com/dp/B01DJHBVS0/ref=cm_sw_r_cp_api_i_B7R097HX2KVSMMR3YE3Q
And wondering if the more expensive ones are worth the cost.
CAP makes a good one that fits nicely over your frag vest
Cap Barbell Short Adjustable Weighted Vest https://www.amazon.ca/dp/B01DJHBVS0/ref=cm_sw_r_cp_api_glt_i_2JXQRJ8J7T9RKNM908DK