Rectangular Inflatable Truck Bed Pool $30

[davester]

As noted in the comments, this holds approximately 340 gallons. Water is 8lbs a gallon. If you fill this up, you're at about 2700 lbs or twice the rated capacity of a half ton truck (F150). Not to mention the weight of the four people in it, which probably bring it up to about 3000 lbs. Good way to wreck your truck.