Bottle rinser / bottle tree issues

[CodKing]

Hey team,

Having some issues with my bottle rinser not squirting like it used to, can't figure out what has changed. Thinking I must have lost an o-ring or something. Anyway, if anyone out there has one of these and could take a pic or two or list the parts it would be much appreciated.

Link to rinser below. (Ps, never pay as much as they are asking there!)

https://www.fishpond.co.nz/Kitchen/Vinator-Bottle-Rinser-Sulphatize...