API Pup Joint is a pipe of non-standard length used to adjust the length of tubular strings to its exact requirement, which is manufactured as per API 5B standard. 
Descriptions； 
1 Standard: API SPEC 5CT&5B
2 Steel grade: J55/K55/N80/L80/P110 
3 Out Diameter for Tubing: 2 3/8"(60.3mm) -4 1/2"(114.3mm) 
 Threads: EUE/NUE 
4 Out Diameter for Casing: 4 1/2"(114.3mm) -20"(508mm), 
 Threads: BTC, LTC, STC. 
5 Lengths: 2,3,4,6,8,10 12 ft (with other lengths available upon request)