Michael R.
if you look at the specs
300000mAh @ appx 3 V = 70Ah at 12V DC. It is a bit misleading.
this has less power it would be equivilent to a 750 Wh for standard use. which means you can use and electric kettle appx 7 times before needing a recharge.
for the price it is on par per Wh as most solar chargers. I would recommend if you have a bonus or cupon then it would come out ahead / or if you want a smaller solar charger.