This is the Core RC 35gram Plate Weight. This weight can be very helpful when needing to add additional weight in your vehicle as it places the weight at the lowest point - under the battery. This weight is about the size of a shorty LiPo (92x47mm) and is only 1mm thick.
Monday, Nov 25 2019 (about a year ago)
Core-RC Brass Under LiPo Plate Weight (35g)
What is there to say other than it does the job and is cost effective. If you are looking for an under battery tuning weight for under $10, well this is a great option! Used it in my xb2 with great results.