Poking around on Amazon, saw this. No particular brand in mind, just curious about whether they actually work, are a gimmick, etc.
UTG 3X Magnifier with Flip-to-side QD Mount, W/E Adjustable Amazon product ASIN B00S2FWRGKView: https://smile.amazon.com/dp/B00S2FWRGK/ref=cm_sw_r_cp_apa_i_lt10DbQ0Q0H6P
UTG 3X Magnifier with Flip-to-side QD Mount, W/E Adjustable Amazon product ASIN B00S2FWRGKView: https://smile.amazon.com/dp/B00S2FWRGK/ref=cm_sw_r_cp_apa_i_lt10DbQ0Q0H6P