With competition-level LiPo batteries mostly available with either 4mm or 5mm plugs, mix and matching different brands with different sizes plugs might an authentic challenge. Arrowmax had checked out the rescue by establishing a 5mm to 4mm down-sizing layer. Various as well as other comparable products and services available on the market now, the coat functions placing into the 5mm plug on LiPo and effortlessly changing it to 4mm. No soldering and very convenient to move from pack to pack. You will maintain your asking cable and ESC experience of the same 4mm plugs and still to be able to utilize LiPo with 5mm conncetion. They come 24K gold plated for optimum conductivity.