I picked up one of these for my 4x4 and I love it. Oscillates, has some good power, and clips to tent poles
LAYOND Grow Tent Oscillating Clip Fan, 6 Inch 25W Grow Tent Fan, Fit for 0.59” to 0.87” Grow Tent Poles, Hand Screws Fixing Solution for Easy and Sturday Install, 2 Speed Levels https://www.amazon.com/dp/B09DST6GTB/ref=cm_sw_r_cp_api_glt_i_5W4QZ072JJ7GVXY8AMJF?_encoding=UTF8&psc=1