For sale is a Gladiator JoeVESA Adapter that I used for my Acer H236HL monitor. There are other Acer models this is compatible with.
Please see pictures for condition. Thanks for looking!Helpful information copied from manufacturer:
Gladiator Joe Monitor Arm/Mount VESA Bracket Adapter Compatible with Acer G227HQL, G237HL, G247HYL, H226HQL, H236HL, SA230 bi, SB220q (See Full Model List Below) - 100% Made in North America

• Our VESA Adapters embody a unique solution to solve the Monitor to VESA hole pattern compatibility issue. Studied and designed to be strong, and avoid bending. We strive to create products that are long lasting and most importantly; keep your monitors safe and secure, all while giving you the luxury of extra desk space and ergonomically friendly options.
• MODELS SUPPORTED: ACER SA230, SB220q, SB220q bi, G227HQL, G227HQL abi, G227HQL bi, G237HL, G237HL bi, G247HYL, G247HYL bmidx, G257HL, G257HL bmidx, G257HU, G257HU smidpx, R240HY offerx, (does not fit the R240HY Abmidx), H226HQL, H226HQL offer, H236HL, H236HL offer, H236HL bmid, H236HL bmjd, H276HL, H276HL bmid, H276HL bmjd, SA240Y ***R271 offer Manufactured in 2018***
• VESA BRACKET PATTERN: 75mmx75mm, 100mmx100mm - Gladiator Joe Inc. has not tested our VESA adapters for vertical use. Please use discretion if you decide to do so.
• Material: Certified Canadian Steel Process: Laser Cut | Acer monitor VESA adapter bracket 100% made in Canada
• Taking in our customers monitor mounting needs, Gladiator Joe Inc. offers a solution to mount your non-VESA compliant monitor. Use our products as the adapter between your specific monitor to desk mounts. Please send us an inquiry for any monitors that you do not see listed, as we are always looking to our customers to further our adapters and other designs.