Model number is CT512M4SSD2BAA (CT512M4SSD2 but with the with 3.5″ bracket).

Technical Specification

Manufacturer ID: CT512M4SSD2BAA
General

Device Type Solid state drive – internal
Bundled with 3.5″ hard drive carrier
Width 7 cm
Depth 10.1 cm
Height 1 cm
Weight 75 g
Hard Drive

Form Factor 2.5″
Capacity 512 GB
Interface Type Serial ATA-600
Features Native Command Queuing (NCQ), multi-level cell (MLC) flash
Compliant Standards S.M.A.R.T.
Performance

Internal Data Rate 500 MBps (read) / 260 MBps (write)
4KB Random Read 40000 IOPS
4KB Random Write 50000 IOPS
Average Latency 1 ms
Reliability

MTBF 1,200,000 hour(s)
Expansion / Connectivity

Interfaces 1 x Serial ATA-600 – 22 pin Serial ATA
Compatible Bays 1 x internal – 2.5″
Miscellaneous

Compliant Standards CE, UL, FCC, RoHS
Manufacturer Warranty

Service & Support Limited lifetime warranty
Service & Support Details Limited warranty – lifetime
Environmental Parameters

Min Operating Temperature 0 °C
Max Operating Temperature 70 °C
Shock Tolerance 1500 g @ 1ms (operating)

Use code SSDCOMP to get this price.

Crucial 512GB M4 SSD – 2.5″ SATA-III – Read 500MB/s Write 260MB/s with 3.5″ Bracket – 3 Year Warranty £287.98 delivered @ ebuyer.com

This voucher SSDCOMP can currently be used with any of the Crucial M4 SSD Range.

It does not matter what capacity you buy, 64GB / 128GB / 256GB / 512GB

Crucial 512GB M4 SSD – 2.5″ SATA-III – Read 500MB/s Write 260MB/s with 3.5″ Bracket

3 Year Warranty

Ebuyer QuickFind code: 339595
Manufacturer ID: CT512M4SSD2BAA

The price at Ebuyer is currently £355
Use discount code SSDCOMP for 10% off, this takes the price down to £319.49, with free delivery.

This is about as cheap as I can find a 512GB SSD hard drive.
Plus it is a Crucial M4, which is a super SSD with a 3 year warranty and lots of review websites always praise this SSD for its speed and reliability.

Price drop again, now down to £319.98, 10% voucher takes it down to £287.98

Crucial 512GB M4 SSD – with 3.5inch Bracket £287.98 @ Ebuyer with 10% off Voucher