Weidmuller terminal blocks 1627160000-ND & 4381-1627160000-ND are the same part. 4381-1627160000-ND is just an internal Digi-Key part number change allowing a smaller quantity purchasing option than the factory 36 quantity package and is only noticed once added to the cart.
Other part names
1627160000-NDR
SLS 5.08/09/180 SN OR BX
4381-1627160000
SLS 5.08/9 OG