For the following Air guns: BSA meteor milbro diana G80 27 Baikral Cometa 300 400 and the No.2 also fits Cometa 5 50 100 with a few coils removed. SPRING MEASURES 19.5mm x 245mm internal diameter is 13.2mm Remember that the number of coils and diameter are important the old spring will be shorter as it is worn out. Remember the legal limit without an FAC is that the gun must be under 12 foot pounds. Requires some knowledge and tools to fit. May need to be shortened to obtain the correct legal power limit.