Czech Airline Travel Service says it has signed a deal to buy five more new Boeing 737 MAX jets.

Spokeswoman Vladimira Dufkova said Wednesday the contract was signed on Dec. 23 and brings to 30 the total number of such Boeing aircraft that Travel Service has recently agreed to buy.

Ken Herbert, managing director and senior aerospace and defense analyst at Canaccord Genuity, expects a number in the 550-600 range.

While it is below the one-to-one or the one book-to-bill guidance provided at the beginning of 2016, it’s not a drastically low number that will spook investors, he explained, adding that 2016 saw good 787 order activity, but 777 orders were lower than expected. GE Capital Aviation Services is the commercial aircraft leasing and financing arm of General Electric. As of December 2016, an order for 75 of the 737 MAX 8 airplanes has been placed. It’s a deal worth $8.25 billion.

“They are in the business of buying airplanes and they will take those airplanes and lease them out to airlines across the world,” Alder said. “With this order, they actually become the largest aircraft leasing company to have the MAX on order,” he added. “They continue to grow their MAX fleet and are the largest owner of a MAX fleet in the world. They have a total of 170 on order.”