Originally from a MacPro, I had this running in my 13" 2014 MacBook Pro with no issues.  

I wiped the drive and installed a fresh copy of big sur (Mac OS 11.7) and updated it.

Heat sink on the back.

Works perfectly. free shipping.

A note about the iMacs, it's a hard/time consuming install - the drive slot is on the back of the motherboard, so it's a disassembly.

Works in these Apple systems:

iMac 21.5" A1418

    iMac14,3 Late 2013: ME086LL/A (2.7 GHz Core i5)
    iMac14,3 Late 2013: ME087LL/A (2.9 GHz Core i5)
    iMac14,3 Late 2013: ME087LL/A (3.1 GHz Core i7)
    iMac14,4 Mid 2014: MF883LL/A (1.4 GHz Core i5)

iMac 27" A1419

    iMac14,2 Late 2013: MD088LL/A (3.2 GHz Core i5)
    iMac14,2 Late 2013: MD089LL/A (3.4 GHz Core i5)
    iMac14,2 Late 2013: MD089LL/A (3.5 GHz Core i7)
    iMac15,1 Retina 5K Late 2014: MF886LL/A (3.5 GHz Core i5)
    iMac15,1 Retina 5K Late 2014: MF886LL/A (4.0 GHz Core i7)

Mac mini Unibody A1347

    Macmini7,1 Late 2014: MGEM2LL/A (1.4 GHz Core i5)
    Macmini7,1 Late 2014: MGEN2LL/A (2.6 GHz Core i5)
    Macmini7,1 Late 2014: MGEQ2LL/A (2.8 GHz Core i5)
    Macmini7,1 Late 2014: MGEQ2LL/A (3.0 GHz Core i7)

MacBook Pro 13" Retina A1502

    MacBookPro11,1 Late 2013: ME864LL/A (2.4 Core i5)
    MacBookPro11,1 Late 2013: ME866LL/A (2.6 Core i5)
    MacBookPro11,1 Late 2013: ME866LL/A (2.8 Core i7)
    MacBookPro11,1 Mid 2014: MGX72LL/A (2.6 GHz Core i5)
    MacBookPro11,1 Mid 2014: MGX82LL/A (2.6 GHz Core i5)
    MacBookPro11,1 Mid 2014: MGX92LL/A (2.8 GHz Core i5)
    MacBookPro11,1 Mid 2014: MGX92LL/A (3.0 GHz Core i7)

MacBook Pro 15" Retina A1398

    MacBookPro11,2 Late 2013 (IG): ME293LL/A (2.0 Core i7)
    MacBookPro11,2 Late 2013 (IG): ME293LL/A (2.3 Core i7)
    MacBookPro11,2 Late 2013 (IG): ME293LL/A (2.6 Core i7)
    MacBookPro11,2 Mid 2014 (IG): MGXA2LL/A (2.5 Core i7)
    MacBookPro11,2 Mid 2014 (IG): MGXA2LL/A (2.2 Core i7)
    MacBookPro11,2 Mid 2014 (IG): MGXA2LL/A (2.8 Core i7)
    MacBookPro11,3 Late 2013 (DG): ME294LL/A (2.3 Core i7)
    MacBookPro11,3 Late 2013 (DG): ME294LL/A (2.6 Core i7)
    MacBookPro11,3 Mid 2014 (DG): MGXC2LL/A (2.5 Core i7)
    MacBookPro11,3 Mid 2014 (DG): MGXC2LL/A (2.8 Core i7)