Custom Shipping Rates for Heavy Large Objects

Hi there,

I am created a custom shipping rate for some large heavy objects that I am introducing to my online shop. When I do a draft checkout it is giving two options to the customer and one is only based on the weight and it is too low. Does anyone know how I can make it work so that the heavy large objects only offer the custom shipping rate that I entered in the shipping details?

Thanks so much,

Kathleen