Not from the maker they supply a roll of tape to build up the ocular, which works fine.
I use shims from my Cobra/Wardy, you can buy the Cobra set but they're not cheap.
Time to "think outside the box" & go a bit "Blue Peter" maybe a section from a sink waste pipe fitting, gutter pipe, or plastic pot of some kind ?
Measure the gap, half it & that's the thickness you need.
Theoben Rapid MK1 177
AA S410 22
Bushnall Scout Range Finder
Hawk 3 x 9 x 40 m.a.p scopes
Deben mini pro lamping system
Get a sheet of 2mm Neoprene off the bay, worked great as a shim on my 2 adaptors.