About this 3D model

Summary i ordered this: https://www.ebay.com/itm/Co2-Laser-Head-Focus-Diode-Module-Red-Dot-Position-DIY-Engraver-Cutter-5V-K40/172731687856?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 and it didn't fit so i modeled this to take a 26mm head like my laser had.