Start with a field brief
Write down the likely target size, soil type, water exposure and the experience of the person who will operate the detector. A dry inland walk, a saltwater beach and a mineralised gold field create different choices. If a condition is unknown, keep it as a question for the supplier rather than treating a single demonstration as a universal result.
Confirm the actual kit
Open the Spanish product page for the model you are considering. Check its coil or sensor, included accessories, software, training and warranty. Ask for the current price and availability in writing for delivery in Spain. The English navigation helps you reach that source; it does not replace a specific offer or promise a find.
A practical reading order
If you are unsure which category to open, begin with the type of result you need: a portable target signal, gold prospecting, wet-ground use or a mapped ground reading. Compare two examples within that category, then write down what you still cannot verify. This avoids asking a supplier to compare devices that answer different questions. For a project in Spain, also check whether access to the site and the planned search are permitted before buying equipment.