Jettec's E36/37 Multipack consists of

2x E36 black ink cartridges and
1x E37 colour ink cartridge.

They are used with the following printers:

Epson Stylus
C42, C42UX, C42SX,
C44UX, C46.

Jettec's E36 are compatible with Epson's T036 (C13T036140).
Jettec's E37 are compatible with Epson's T037 (C13T037140).