Due to the UK being shut off from the European mainland because of the new Covid-19 mutation it is very likely your order will be delayed until further notice. There is nothing we can do about this at this point in time
By placing a cover over the sandbox, the quality of the sand is guaranteed. There can not be leaves or other debris in the sand and you also prevent cats from using the sandbox as a litter box. Rather hygienic. When purchasing a sandbox cover, make sure that it is suitable for the dimensions of your sandbox.