Probably won’t find a sleeve unless you have a friendly fitter using a Trackman indoors. You’ll need to confirm that five iron simulators can p/u the sensor in the ball. Not all have been upgraded to do so. Trackman was the first to utilize the technology. The original price was around $70 a dozen, so a sleeve from a fitting location would still be upwards of $20 dollars. Or a dozen direct for yourself

Messaged five iron and they said their trackmans are optimized for RCT balls.

I use them often. Definitely can see a difference in accuracy. Worth it I say.

I use a Mevo+. I purchased a dozen of the ProV1 and -ProV1x. I ordered ProV1x ones that should arrive today and will do a comparison across the 3…I’ve found more consistency with the spin numbers for them…Much closer in line with what I see on Trackman which I usually do 1 or 2 times per year to check my gaps…However, I do get an occasional whacky reading…For example, My 9 iron (T100s) usually gives me around 6700rpms and my T200 irons around 6400. But, occasionally there will be a 12,000 one in there! Very odd…That happens maybe 1 out of 20 shots though.