Beach RC says.... This is a replacement Tekno RC Fuel Tank and Accessories (revised, NB48 2.0, IFMAR legal)

This revised NB48 2.0 fuel tank retains the same outside dimensions and mounting positions as the original while improving the internal baffles and fuel nipple. While the ‘stuck clunk’ issue only affected a handful of customers, we thought it was best to resolve this issue for good. Additional internal baffles now hold the clunk securely in the center of the tank, reducing the chance that the clunk can become kinked during a hard crash. Also included is a new extended length fuel nipple that more securely grips the internal fuel line. This revised tank is a direct replacement for the original NB48 2.0 tank (TKR9340).