Kirk L-Bracket for Gripped Canon 70/80D
Price: $75.00
Item condition: 9+ Shows little or no signs of wear
Payment method: PayPal
Shipping instructions: USPS Priority
This is the discontinued 1-piece L-Bracket for a Gripped Canon 70/80D.
Suspect it would work with a 90D since it also uses the BG-E14 although I've not confirmed fitment on a 90D. Check the pics and decide for yourself.
For reference: https://www.adorama.com/kirbl70dg.html?discontinued=t
Additional Pics: https://flic.kr/s/aHsmKz1rNH