This simulated nozzle is designed to replace Estes part no. 072665 nose cone/nozzle combination for BT-60 size airframe tubing.

Estes kits using this nozzle are:

ESAM-58 (kit# 0661; sold only at Hobby Lobby stores in the USA)
Conquest (kit# 7230)
QCC Explorer (kit# 3221)
SA-2061 Sasha (kit# 7271)
Solar Warrior (kit# 3225)

You can download it for free from Thingiverse and print it.
https://www.thingiverse.com/thing:4119920