DERBY TOKAI Premium 100 Double Edge Razor Blades, Black, DBYBLK, 5 Count (Pack of 20) - £5.86 @ Amazon

Mentioned these a few days ago, the price is trickling down again! Also on Buy 4, Save 5%

(made into a Deal post by me back in May 2021 when they were £5.47! - seem to have favourable feedback - I know most people hate Derby Greens (Extra), though!)

For some reason, some of the Amazon images are of the half-blades, but these are double-edged blades. - see here

Age Verification Required: This product is not for sale to people under the age of 18 and will require an online age verification check. To confirm the recipient is over 18, valid photographic ID with a date of birth may also be required upon delivery. The driver will input your year of birth into their device and may then require an ID check to complete the age verification process. The driver will not be able to access your information once the delivery is complete. See Details

BOX DERBY PREMIUM BLACK RAZOR BLADES IN SWEDISH STEEL- 100 BLADES
Box Derby Premium Black razor blades in Swedish steel- 100 blades. Derby Premium are the new razor blades produced by Derby Tokai ( for safety and straight razors like shavette). Derby Premium Black blades born from the experience grown up in decades with the other blades produced by the factory, but they open up new horizons using Swedish steel and eliminating the risk of the blade defect. High performance blades, Derby Premium Black are the new arrival point for Derby, sweet, perfectly sharpened by excellent duration. They don't scratch and don't irritate the skin. Blades by great value for money.

Manufacturer: Azmusebat, Istanbul ( Turkey )
How many blades are there in every package: five blades wrapped in waxed paper individually. Do you want to know our opinion on some of the most famous razor blades on the marketplace? Read our blog article

(The blurb reads as if it's been translated - poorly! )

SPECIALIZED:- Made of Chromium-Ceramic-Platinum-Tungsten and Polymer Coated Stainless Steel Best for Barbers Shavings and for barber Shops

ERGONOMIC : Suitable for all cut throat / Shavette Type Razors Including shaving factory, Dovo, Focus, and parker.

These Single Edges Blades Perfect for barber Razors and Exchange able ,Sliding Barber Razors,

Derby Premium Single Edge Blades, Made of Swedish Steel

VERSATILE : Only when high-quality materials, stylish and effective functionality are perfectly combbind in a single product, Says Derby Mean Professional Maximum Quality, Our Passion is To give everyday object of the male everyday upgraded, And not to the next possible ,But the highest possible level, A good Razor Blades is sharp and beautiful, Consistently well product for consistently man!

CONVENIENCE :- You Don't Need to Split Double Edge Razor Blades any More, These Blades are Perfectly design for Barbers razors for Wet Shaving and Perfect Single Edge Blades

All Derby Razor Blades are Manufactured from stainless razor blade steel strip from Sweden.

All Derby Razor Blades are perforated, hardened and ground by utilizing most advanced equipment.

All Derby Razor Blades cutting edges are deposited with CHROMIUM- CERAMIC, TUNGSTEN AND PLATINUM by advanced Spluttering Equipment for optimum EDGE STRENGHT thus longer shaving life.

All Derby Razor Blades coated with a polymer for optimum SHAVING COMFORT.

From beginning to end, all Derby Razor Blades are subjected to severe Quality Control Inspection at every stage of manufacturing process by utilization of unique quality control equipment.

All Derby Razor Production is granted with TS-EN-ISO 9001:2000 QUALITY MANAGEMENT SYSTEMS.

• Made of Swedish Steel
• Highest quality blades made to fit different double edge safety razors
• Each blade is individually wax paper wrapped

Keepa says (Amazon prices only - not the best price ever-ever - which was £5.36 in June 2021 - but not a bad average. Best price in the past 18 months +), keepa.com/
BigD's Derby Premium Review | Badger & Blade (badgerandblade.com) - from May 2019 (he prefers the Derby Usta blades, it seems)

Refined Shave says in November 2017: refinedshave.com/der…ew/Amazon reviews, here
This guy is unhappy, though!There's a woman face-shaving comparing Derby Extra to these Derby 'Tokai' Premium blades (wouldn't want to assume why, but nice to see a female reviewer?).
Using these blades with the Merkur Progress (video from November 2019) - Derby Premium DE blade is it better than the Derby Extra? - YouTube