This paperweight has a white, stripy spiral around a core of green and reminds me of a helter-skelter spiraling slide, hence its name. It has air bubbles along the spiral, almost as if they are taking a ride down it. It makes a lovely decorative piece if not being used to keep papers in order.
The main picture has a twenty pence piece to help with scale, the second picture is of the other side of the weight.
The dimensions are approximately: 8cm diameter by 5.5cm tall, it weighs 646g so heavy enough to keep wayward papers in place.