Tyres, batteries and parts, by exact fitment
The register knows which tyre and which battery fits which vehicle, so you do not have to remember a size. Start from your vehicle and it lists what fits it, or type the size you already run, 295/90R20 and the like, and it lists the vehicles that take it.
Where a maker prints an MRP we show it and say it is the maker's. Where no MRP is printed, and for most fitting and service work, the shop names the price: we say so rather than invent a figure. Near your PIN you also get the shops and the mechanics who do this work.
A wrong size is an expensive mistake that shows up months later as uneven wear. If your vehicle is not on the register or the fitment looks wrong, open a job card and a person checks it.