Drop through decks have the truck baseplate (the section that fixed the truck to the deck) mounted on the top of the deck, going through a slot, with the hangars then reattached below the deck. This gives a super low centre of gravity, excellent for steezy carves. Pintails are a common shape - very manoeuvrable and suited for cruising and carving on flat ground or mellow hills. We have an in-depth article of the PINTAIL VS DROP-THROUGH LONGBOARDS