Air suspension is extremely reliable and normally you wouldn’t need to change O rings unless you've taken the struts apart or the vehicle has been in storage for a while. Then the air suspension parts would need to be serviced.
In our online shop we stock O rings for our own make and TA Technix struts.
A selection of O rings can be found here.
We might be able to supply other sizes, please call us on 0800 772 0315 or send an email to ENQUIRIES@AIRRIDE.UK