Injector Dynamics seal kits are supplied individually - so if you have a 4 cylinder engine you will need to order 4 seal kits.
To find the correct seal kit for your injectors simply find the original part number for your injectors.
For example Evo 1-9 1050cc is 1050.60.11.D.4 the seal kit part number is SK.60.11.D
To search the number you need - Remove the injector size in this case 1050 & the last number which will be .4 .5. .6 .8 etc.
Add SK. to to the beginning and you have the seal kit part number you need.