They're very simple, BTP wraps, made from PUL. They come in snaps only, and can be used with fitted nappies, pad shaped inserts and prefolds/terry nappies held together with pins or a Nappi Nippa.
There are two different types - on the left is one without white edging, and on the right is one with edging. The type without the edging has two 'flaps' inside, at the back and front, to help hold a pad type insert into place. The type with edging has just one flap at the front.
I have found these to be a reliable nappy wrap, and had a lot of success using them overnight (14 hours!) in combination with A Mama Knows bamboo nappies with an extra bamboo insert. They wash and wear well, and for only £3.19 each (less if you buy a multipack), they're a bargain.