The Hongsen HS-ML-1234 is a refrigerant recovery machine specifically designed for the recovery of R-1234yf, an environmentally friendly refrigerant. This model is part of the trend in the HVAC industry towards more sustainable refrigerants that have lower global warming potential than traditional options. https://www.industrywaala.com/product/hongsen-taa0652-hs-ml-1234-lock-type-r1234yf-quick-coupler-l-female-with-adapter