Here's one
You always get more info off USA sites - so you get 20% chemical - if my maths are correct you would use 2.1 litres of Hypo a min
which would give you 1.4% strength
Max Pressure: 5500 PSI
Max Temperature: 190°F
Up to a 10% injection draw rate
Made in the USA
Orifice: 2.2 mm
Flow Rate: 3.0 to 5.0 GPM
Inlet: 3/8" NPT-M
Outlet: 3/8" NPT-M
Hose barb: 1/4"
Materials: Stainless Steel
Weight: 0.25 lbs.
Or this - you can buy them to mix from 1% to 5%
already has a qr to fit on the lance and another qr for the nozzle
Stainless Injector with couplings (Blue, Red or Clear pipe)
High quality stainless steel foam injector including stainless steel quick couplings. Dosage orrifice plate at required % with pick up tube and strainer.
(Different orrifice percentages at 1% to 5%)