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The PRB-4220 is a right-handed set of RATIO® Calibrated Machine Heads for BASS that use a 2 + 2 configuration.
In order to achieve higher gear ratios, Ratio are the world's first machine heads using a double envelope gear design with a hardened steel gear. Amazingly smooth and super strong.
Headstock Configuration 2 + 2 Ratio Tuned Machine Heads: The New Standard In Tuning Technology
Gear ratio: unique for each string position - one turn-one tone Peg holes diameter required: 35/64" (14mm) String post diameter: 0.547" (13.9mm) String post length to string hole: 1.030” (26.1mm) Weight per single machine head: 1.86oz (53g) Weight per set of four: 7.44oz (212g) String diameter up to 0.98 gauge (or larger if taper-wound) Includes 4 machine heads, mounting screws, and bushings
RATIO® patented gear technology RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.
From Low E to G - 36:1, 30:1, 20:1, 18:1.
We balanced the gear ratios to each string simplifying the tuning process.
With RATIO®, a half-turn is a semi-tone!
Every string reacts the same to any tuning adjustment. Predictable, precise tuning, on every string.
All items are professionally packed for safe transit
Tracked UK delivery options available at checkout
Orders placed before 1pm (Mon–Fri) are usually dispatched the same working day
Guitars may require 1–2 additional working days for final setup
UK Delivery: Standard and next working day options available. Some remote areas may incur an additional charge — we’ll always contact you before dispatch.
International Shipping: Worldwide shipping available — please contact us for a quote before ordering.
For full delivery options, setup information, and international pricing, 👉 View our Shipping page: https://www.guitarwarehouse.co.uk/pages/shipping
Online Orders – 14-Day Returns (Distance Selling Regulations) Customers who make a purchase online or via distance selling are entitled to return an item within 14 days of receipt, in accordance with the Consumer Contracts Regulations. Items must be in unused condition and returned with all original packaging and documentation.
Refunds will be issued to the original payment method once the item has been inspected and confirmed to be in resalable condition.
Return shipping is the responsibility of the customer unless the item is faulty or supplied in error.
In-Store Purchases Items purchased in-store are not eligible for a refund. However, we do offer exchange or a store credit (gift card) for in-store purchases returned within 14 days, provided they are in their original condition with proof of purchase.
Exclusions Please note that custom orders, modified items, B-stock, clearance items, and goods obtained through part exchange are non-refundable, unless faulty.
Partial Refunds There are certain situations where only partial refunds may be granted, at our discretion. These include, but are not limited to:
Guitars returned with protective plastic film removed from pickguards or pickups.
Items showing signs of use or handling.
Missing or damaged original packaging, tags, or accessories.
All returns are inspected upon receipt. If a return does not meet the conditions above, we reserve the right to refuse it or issue a partial refund.
New Items — 12-Month Warranty
All new products sold by Guitar Warehouse are covered by a 12-month manufacturer’s warranty, in line with UK consumer law.
This warranty covers manufacturing defects and faults that occur under normal use. In the event of an issue, we will assist with the warranty process and liaise with the manufacturer or authorised service centre where required.
This warranty does not cover:
Normal wear and tear
Damage caused by misuse, neglect, accident, or unauthorised repair/modification
Consumable items (such as strings, valves, batteries, etc.)
Pre-Owned Items — 3-Month Warranty
All pre-owned items are supplied with a 3-month Guitar Warehouse warranty.
This covers faults that arise from normal use and were not apparent at the time of sale. All pre-owned instruments and equipment are checked, tested, and set up prior to sale to ensure they are fully functional.
This warranty does not cover:
Cosmetic wear consistent with age or prior use
Damage caused by misuse, neglect, accident, or unauthorised repair/modification
Proof of purchase is required for all warranty claims.
Warranty claims must be reported as soon as a fault is identified.
Warranty is non-transferable and applies to the original purchaser only.
Your statutory rights under UK consumer law are not affected.
For warranty claims on distance sales, customers are responsible for safely returning the item to us for inspection. Where a valid warranty fault is confirmed, we will cover the cost of returning the item to the customer.
If you have any questions about warranty coverage, please contact us — we’re always happy to help.
