Vintage stretchy Patagonia capilene tank size M

I used to wear these cool Patagonia tops as casual wear. Also good for yoga and such. Form fitting substantive thickness stretchy material. Hard to capture the weight of the material. Form fitting, did I say? I always washed in cold water and line dried. Now I wear more loose and forgiving tops. This needs to find a new home! This is the same size as the other Patagonia tank I have listed that is an M, so even though the size marking is not legible I am confident it is an M.