Introduction
That Happymodel Larva-x is a great value bind and fly ultralight toothpick-style quad which I reviewed and provided and improved tune for here. This is their first model to come without a battery which is due to the fact that many international shipping suppliers are banning lipo batteries from shipment. Stock propellers are the Emax Avan Rush 2.5 but due to supply issues HQ Prop 2.5x2.5x3 are also included as spares. My full review is here where I flew almost exclusively on the HQ 2.5x2.5x3, not because they were necessarily better but because they were less stiff and transmit less impact to what is a relatively weak motor (see my review for more details including a response from Happymodel).

If you're new here you'll find I'm never satisfied with status quo and like to tinker. Propellers and batteries are dispoable items so I've chosen to share the outcome of my tinkering with these. What I did find however is that this quad is very sensitive to these combinations and although some improvements can be had, there are also some very poor combinations that are inefficient and noisy with less than stellar performance.

The Happymodel Mobula7 (reviewed here), Eachine Trashcan (reviewed here) and many other brushless whoops use generic 4 bladed 40mm props that are cheap and readily available but are they the best? Simply put, no. They are from a toy grade mould and we have accepted them because when these brushless whoops were first released there was simply nothing else available. Fast forward to the present day with the growth in popularity of these models there are a lot more options, some readily available internationally, some not so much. In this article I'll give you my experiences on what I found to be my favourite prop and the justification of why (what it is I look for in a propeller).

What props are available?
If you're in North America probably the full list of what is below. I'm not in North America though so I was limited to what was locally available and what had low (or no) international shipping cost. Therefore this is not an exhaustive test, my approach was more on of pragmatism. ​

My Findings
I'll compare all my findings back to a baseline result of the stock props for simplicity

Gemfan 1636 (4 blade)
I used these when I was running the v3/trashcan frame which I blogged about here. These were a direct improvement over the stock props in all aspects but were a little more amp-hungry. Grip and speed was improved and control felt better. Props are well balanced but heavier than stock. They are extremely durable especially when you consider the protection afforded by the ducts. You will achieve hover at very low throttle

These props are a good upgrade but not my personal favourite.

Note: These are more like 41mm than 40mm and frustratingly don't quite fit in the ducts of of the v3/trashcan frame - the ones you see above were painstakingly sanded down and even then still rubbed every now and then. I hear TBS props have the same issue