Blade numbers are cut lengths, and picking the right one is most of getting a groom right. A 5f leaves more coat than a 4f does — the higher the number, the shorter the cut, and the f stands for full tooth, which gives a smoother finish than a skip-tooth blade on a coat that is in reasonable condition.

This is Wahl's Prime Series, made for the KM Supera Pet Clipper and the KMC+ Clippers. Every Prime blade is precision ground from solid high-carbon steel, and the range is designed around a quick change system, so a blade clips and unclips for maintenance or replacement without tools. They are grooved so they stay cool through longer sessions, which is what stops a blade becoming uncomfortable partway through a dog. Being solid metal, they can be re-sharpened several times before they need replacing.

• Prime Series 5f blade for the KM Supera and KMC+ clippers
• Precision ground from solid high-carbon steel
• Quick change system, no tools needed
• Grooved to stay cool during long sessions
• Can be re-sharpened multiple times before replacement

Check the machine, and check the coat. This blade fits the KM Supera and the KMC+ and is not universal — a blade that does not match the clipper is no use to anyone. On the coat side, a full-tooth blade is for a clean, brushed, mat-free coat; run one through matting and it drags rather than cuts, which hurts the dog and blunts the blade. Keep it oiled, clear the hair after every dog, and stop if it gets hot: a hot blade burns skin faster than most people expect.

Who it's for: groomers and serious home users running a Wahl KM Supera or KMC+ who want a longer cut than a 4f leaves.