The Fittings | M16 Connection Spring is a small stainless steel compression spring used to maintain positive contact and secure the M16 glass-to-metal heating connection on VTA wiped-film distillation equipment. It ensures consistent thermal contact between the glass evaporator body and the M16 heating line connector, preventing heat loss and maintaining precise temperature control during distillation runs. An inexpensive but critical OEM maintenance part for VTA VKL and VKS series distillation systems.